Every DJ term, with a number behind it.

BPM

BPM — beats per minute — counts how many beats land in sixty seconds. It is the first number a DJ checks, because two tracks have to agree on tempo before anything else about them matters.

128 BPM is the busiest shelf in the catalog with 35,264 tracks stored there, and 243,477 of 443,680 tracks with a detected tempo (54.9%) sit between 120 and 130.

Bar

A bar is four beats in 4/4 time — one full cycle of the kick pattern. DJs count in bars rather than seconds because a bar is the same length of music at any tempo, and seconds are not.

At 128 BPM — the catalog's busiest tempo, 35,264 tracks — one bar lasts 1.88 seconds, so the median track at 5:48 runs about 186 bars.

Phrase

A phrase is a block of bars a track is built from, usually 8, 16 or 32. Electronic music changes at phrase boundaries, so a mix that starts on one keeps both tracks structurally in step.

243,477 of 443,680 tracks with a detected tempo (54.9%) sit between 120 and 130 BPM, where a 32-bar phrase runs 59.1 to 64.0 seconds.

Half-time

Half-time is a groove that feels half as fast as it counts — the snare lands every other bar instead of every other beat. Drum & bass written at 174 BPM is felt, and often detected, at 87.

46,690 of 443,307 tracks with a detected tempo (10.5%) are stored below 95 BPM, and 81.9% of drum & bass is among them.

Double-time

Double-time is the mirror of half-time: a groove counted at one tempo and felt at twice the rate. A 70 BPM beat played as 140 is the same record, counted differently, and mixes on the same grid.

The octave is lopsided in both directions: 70 BPM holds 2,883 tracks against 17,961 at 140, while 87 holds 10,880 against 173 at 174.

Four-on-the-floor

Four-on-the-floor is a kick drum on every beat of the bar. It is the rhythmic base of house, techno and trance, and it is the reason those genres mix into each other so easily.

273,725 of 443,460 public tracks (61.7%) are tagged into the house, techno and trance family built on it, at a median of 126 BPM.

Beatmatching

Beatmatching is lining up two tracks so their beats land together — matching the tempo, then nudging the phase until the kicks coincide. It is the base skill every other mixing technique sits on top of.

The median tempo gap DJs actually mix across here is 1.0 BPM, and 81.5% of 7,243 hand-sequenced transitions land within 3.

Pitch fader

The pitch fader is the slider that speeds a track up or slows it down, usually by up to 6 or 8 percent. It is how two records are brought to the same tempo before they are mixed.

A ±6% pitch fader reaches furthest from 127 BPM, where it covers 266,249 of 443,680 tracks with a detected tempo (60.0%) — more than it reaches from 128, the tempo the catalog actually stocks most.

Beatgrid

A beatgrid is the map your DJ software lays over a track marking where every beat falls. Once it is right, sync, looping and quantise all work; once it is wrong, everything built on top of it is wrong too.

Our analyser reads 443,442 of 443,460 public tracks as 4/4 — and still flags its own tempo reading as uncertain on 71,506 of them, one track in six.

Tempo bridge

A tempo bridge is a track played to move a set from one tempo neighbourhood to another — fast enough to follow what came before, slow enough to lead into what comes next, so the change never happens in one jump.

Between the house shelf at 128 BPM and the 140 where psy-trance and dubstep sit, the catalog holds 43,805 tracks at 132–138 BPM — 9.9% of everything with a detected tempo.

Beat

A beat is the steady pulse you tap your foot to — the unit tempo is counted in. Four of them make a bar in the 4/4 time nearly all dance music is written in.

At 128 BPM — the catalog's busiest tempo, 35,264 tracks — a beat lasts 0.47 seconds, so a bar is 1.88 and a 32-bar phrase is 60.0.

Downbeat

The downbeat is the first beat of a bar — the "one" a DJ counts to. It is where the kick lands hardest and where every phrase, drop and transition is aligned from.

100.0% of the catalog — 443,442 of 443,460 public tracks — reads as 4/4, which is what makes one correct downbeat imply the whole grid.

Time signature

A time signature says how many beats are in a bar and which note value counts as a beat. Dance music is almost entirely 4/4 — four quarter-note beats to the bar, every bar.

443,442 of 443,460 public tracks read as 4/4 — 100.0% — leaving 18 in the whole catalog that do not.

Swing

Swing delays every second sixteenth note so the rhythm lopes instead of marching. It is the difference between a house record that rolls and one that sits rigidly on the grid.

Our groove reading — swing and rhythmic pull — runs at a median of 71 across 443,242 analysed tracks, and it tracks danceability at 0.47.

Syncopation

Syncopation puts accents where the beat is not — on off-beats and in the gaps between them. It is what makes a groove pull against the pulse rather than restate it.

A syncopated record wants a simple one underneath it — two busy off-beat patterns fight for the same space and turn to mush.

Camelot key

Camelot notation renames every musical key as a number from 1 to 12 plus a letter — A for minor, B for major. 8A is A minor. Codes next to each other on the wheel share most of their notes.

8A is the most crowded code in the catalog at 8.13% of 443,787 tracks with a detected key, and 1B the thinnest at 1.64% — a 4.9× spread across 24 codes.

Harmonic mixing

Harmonic mixing means choosing the next track by key as well as tempo — staying on the same Camelot code, moving one step around the wheel, or swapping between the major and minor of the same number.

70.5% of 7,243 transitions DJs sequenced by hand here are textbook Camelot moves, against 18.3% if the same keys were drawn at random — 3.8× chance.

Open Key

Open Key is a second notation for the same wheel Camelot describes. It numbers the positions differently — C major is 1d rather than 8B — and uses m and d for minor and major, but the mixing rules are identical.

The most crowded position in the catalog is 8A in Camelot — 1m in Open Key, A Minor — with 36,060 of 443,787 tracks that carry a detected key, 8.1% of them.

Relative major and minor

Relative major and minor are two keys built from the same notes — A minor and C major, for instance. On the Camelot wheel they share a number and differ only by letter, which is why moving between them always works.

271,306 of 443,057 analysed tracks are in a minor key — 61.2% — against 171,751 in major, so for most records the relative switch is a move into the light.

Energy boost

The energy boost is the +2 move on the Camelot wheel — two positions clockwise, same letter — which lifts a mix by a whole tone. Every chart lists it as a legal move, and it is the one DJs reach for least.

Across 7,243 transitions sequenced by hand here, the +2 energy boost appears in 2.29% — against 4.79% expected by chance. DJs use it at 0.48× the rate a shuffled running order would.

Tonal shift

A tonal shift moves one position around the Camelot wheel and switches between major and minor at the same time — 8A to 9B, say. No standard chart lists it, and it is the most common rule-break DJs make.

The diagonal appears in 12.1% of 7,243 hand-sequenced transitions against 7.7% by chance — 1.6× — and accounts for 41% of every move that breaks the textbook rules.

Key lock

Key lock — master tempo on a CDJ — holds a track at its original pitch while you change its tempo. Without it, speeding a record up raises its key and quietly undoes whatever harmonic mixing you had planned.

One semitone is a 5.95% tempo change, so a ±6% fader spans almost exactly one — and from 128 BPM that fader reaches 252,478 of 443,680 tracks with a detected tempo.

Musical key

The musical key is the note a track resolves to plus whether it is major or minor — A minor, F major. It is the same information a Camelot code carries, written the way a musician would write it.

10 of the 24 keys have two names — F♯ minor is also G♭ minor — and 31.0% of the 443,787 keyed tracks in our catalog sit in one.

Energy

Energy is a 0–100 reading of how hard a track hits, taken from loudness, spectral drive and percussive weight. It is the dimension that decides where in a set a track belongs rather than what it mixes with.

The median track in the catalog reads 56 for energy across 443,242 analysed tracks, and the scale is clipped at the top — 100 is a tie, not a rank.

Groove

Groove is a 0–100 reading of swing and rhythmic pull — how much a track moves rather than simply pounds. It is what makes a quiet record danceable and a loud one stiff.

Groove runs high across the catalog — a median of 71 over 443,242 analysed tracks — and it barely tracks energy at all: the correlation between the two is -0.11.

Valence

Valence is a 0–100 reading of musical mood — bright and lifting at the top, dark and tense at the bottom. It is the dimension that decides whether two tracks feel like they belong to the same night.

Valence never reaches either end of its own scale in this catalog: across 443,242 analysed tracks the darkest reads 18 and the brightest 79, with a median of 45.

Danceability

Danceability is a 0–100 reading of how easy a track is to move to — steady tempo, strong beat, regular rhythm. It is not the same as energy: a slow, quiet record can be highly danceable.

Danceability sits high and tight — a median of 73 across 443,242 analysed tracks, spanning only 27 to 96.

Texture

Texture is the tone of a track rather than its rhythm — how bright, how warm, how bass-heavy, how percussive. Two tracks can agree on key and tempo and still clash on texture.

The median track reads 88 for bass weight, 59 for brightness, 44 for percussive ratio and 37 for warmth across 443,242 analysed tracks.

Chemistry

Chemistry is Mixgraph’s score for how well two tracks mix, from six weighted dimensions: harmonic key, tempo, energy, groove, mood and vocals. It rates the pair, not either track on its own.

A chemistry score of 85 or better is rare by construction — 0.0917% of 2,999,426 randomly drawn cross-artist pairs reach it — which is what makes the number worth reading.

Instrumental

An instrumental is a version of a track with the vocal taken out, or a record that never had one. DJs use them to lay an acapella over the top, or to stop a vocal-heavy stretch of a set crowding itself.

Our analyser puts 165,610 of 443,242 tracks above 0.80 on instrumentalness and only 17 below 0.20 — a floor that empty is a fact about the detector, not about how many records have a vocal.

Loudness

Loudness is a track’s average level in decibels below full scale, so every value is negative and closer to zero is louder. It decides how far you move the gain, not how hard the record hits.

Eight tracks in ten sit between -13.32 dB and -8.45 dB — a band 4.9 dB wide around a median of -10.68 — while the catalog as a whole runs from -85.23 to -2.80.

Vocal chop

A vocal chop is a voice cut into short fragments and replayed as a melodic or rhythmic part. It reads as a hook rather than as a lyric, and it is one of the most recognisable sounds in modern dance music.

A vocal chop behaves like a synth line, not a voice: pitched, locked to the grid, and able to clash where a sung phrase would not.

Kick

The kick is the low drum that states the beat — in most dance music, on every one of the four beats in a bar. It carries the pulse and most of the energy a floor actually feels.

273,725 public tracks — 61.7% of the catalog — are tagged into the house, techno and trance family built on a four-to-the-floor kick, at a median of 126 BPM.

Snare

The snare is the sharp drum that answers the kick, usually on beats two and four. In dance music it is often a clap or a layered mix of both, and it is what tells you where you are in the bar.

46,690 of 443,307 tracks with a detected tempo — 10.5% — sit below 95 BPM, and most of that is fast music whose snare pattern fooled the detector.

Hi-hat

The hi-hat is the high, ticking percussion that fills the space between kick and snare. Open hats on the off-beat are the sound that makes house music move.

Hats are the safest thing to leave overlapping — the top end is the one range where two records rarely fight.

Bassline

The bassline is the low melodic part that moves underneath the drums. It carries the track’s harmony as much as its weight, which is why two of them at once clash in a way two melodies do not.

Bass weight runs at a median of 88 across 443,242 analysed tracks and is clipped at the top of its scale — this catalog is built almost entirely from bass-led music.

Sub-bass

Sub-bass is the lowest band of a record, roughly below 60 Hz — the part a club feels through the floor rather than hears. It is where most of a track’s physical impact lives.

Sub is nearly inaudible on headphones and enormous on a rig, so it is the one band you cannot mix by ear alone.

Top line

The top line is the main melodic or vocal hook sitting above everything else — the part you hum afterwards. It occupies the upper mids, which is the most crowded space in any mix.

Brightness — how much of a record sits in the upper range where a top line lives — runs at a median of 59 over 443,242 analysed tracks, and is clipped at the top of its scale.

Three-band EQ

A three-band EQ splits each channel into low, mid and high and gives you a knob for each. It is the primary tool for deciding which parts of two records are audible at any moment.

The three bands map onto what our analyser reads: bass weight at a median of 88, warmth at 37 and brightness at 59 across 443,242 tracks.

Kill EQ

A kill EQ removes a band completely when the knob is turned fully down, rather than merely attenuating it. On a mixer with true kills, taking the bass to zero leaves genuinely nothing below the crossover.

A true kill turns the low band into a switch: one record owns the bass or the other does, with nothing in between.

Filter

A filter removes everything above or below a moving cutoff point. A high-pass strips the bottom away as you turn it up; a low-pass takes the top off as you turn it down.

A filter moves a record along the same axis our analyser reads: brightness runs 2 to 100 across 443,242 tracks, at a median of 59.

Gain

Gain sets how hot a track arrives at the channel before anything else touches it. It is a correction for how the record was mastered, not a volume control for the room.

Set gain so the channel meter peaks in the same place on both decks, then leave it alone and mix with the faders.

Headroom

Headroom is the gap between where your signal is sitting and the point where it distorts. It is the room left for the loud parts, and for whatever you do to the channel next.

Leave headroom for the moment two records are both playing — that is when a mix demands the most and has the least.

Clipping

Clipping is what happens when a signal exceeds the maximum a system can carry: the peaks are cut flat, adding harsh harmonics. In digital audio the ceiling is 0 dBFS and there is nothing above it.

Red on the master is not "loud" — it is the sound breaking, and on a club rig it arrives as pain rather than impact.

dBFS

dBFS means decibels relative to full scale — the digital measurement where 0 is the loudest a file can be and everything else is negative. A track at −10 dBFS sits ten decibels below the ceiling.

Nothing in the catalog reaches the ceiling: the loudest master we hold sits at -2.80 dBFS, the quietest at -85.23, and the median at -10.68 across 443,242 tracks.

Limiter

A limiter is a compressor with an absolute ceiling: it lets everything through until a set level, then refuses to exceed it. Mastering engineers use one on every record you own.

A limiter on a club system is a safety net, not a mixing tool — if it is working hard, fix the gain instead.

Compressor

A compressor reduces the level of anything above a threshold, narrowing the gap between the loud and quiet parts. The result can then be turned up as a whole, which is how records get their density.

Compression is why a club record feels dense without any single moment being especially loud.

Transient

A transient is the short burst of energy at the start of a sound — the click of a kick, the snap of a snare. It is what makes percussion readable and what beat detection listens for.

Percussive ratio — how much of a record is transient rather than sustained — runs at a median of 44 across 443,242 analysed tracks, spanning 3 to 73.

Ducking

Ducking pulls one signal down whenever another plays — almost always everything else dropping on each kick. It is the pumping motion at the heart of most house and trance.

Two heavily ducked records pump against each other unless their kicks are locked — the motion is only pleasant when it agrees.

LUFS

LUFS means loudness units relative to full scale — a loudness measurement weighted to match how ears hear rather than what a peak meter reads. Streaming platforms and DJ software both normalise to a LUFS target.

Records first released before 2000 sit 3.33 dB quieter than the 2020s across our catalog — -13.47 against -10.14 — which is the loudness war, measured.

True peak

True peak is the highest level a waveform actually reaches between the samples that describe it. A file whose every sample sits below the ceiling can still overshoot it once a player reconstructs the sound.

A file can read under the ceiling on every sample and still clip the moment a player turns it back into sound.

Gain normalisation

Gain normalisation sets every track to the same measured loudness automatically, so a quiet record and a loud one arrive at the channel matched. It corrects for mastering, not for how hard a record hits.

Nearly half the transitions DJs build here need under a decibel of gain correction — one in ten needs three decibels or more, and the widest in the corpus is 12.36.

Mono sum and phase

Summing to mono adds the left and right channels together. Anything out of phase between them cancels rather than adding, which is why a wide stereo bass can lose most of its weight on a mono system.

Keep the low end mono: a club rig sums the bottom in the room whether or not your mixer does it first.

Arpeggio

An arpeggio plays the notes of a chord one after another instead of together. In electronic music it usually arrives as a fast repeating pattern from an arpeggiator, running in time with the tempo.

Treat an arp as a lead, not as texture: give it the mix on its own, or filter one back.

Fill

A fill is a short break in the drum pattern — a tom run, a snare roll, a beat left out — marking the end of one section and the start of the next.

Use fills as the boundary marker: when one lands, the next phrase is starting, and that is where a mix belongs.

Stab

A stab is a short, hard chord hit — an organ, a brass sound, a synth chord — cut off almost as soon as it sounds. It carries harmony without occupying space, which is why house music is built on them.

Stabs mix where pads do not, because each hit is over before the other record’s harmony has to agree with it.

Reverb

Reverb is the sound of a space — hundreds of reflections arriving after a sound and fading. As a DJ effect it is used to smear the tail of one record into the arrival of the next.

Reverb is a tail, not a texture — use it to end something, and pull it back before the next low end arrives.

Delay

Delay repeats a sound after a set time. On a DJ mixer that time is locked to the detected tempo, so the setting is a beat division rather than a number of milliseconds and the repeats land on the grid.

At 128 BPM — the catalog's busiest tempo, 35,264 tracks — one beat of delay is 469 ms, a half-beat 234 ms, and a full bar 1,875 ms.

Ping-pong delay

A ping-pong delay alternates its repeats between the left and right channels, so each echo bounces across the stereo field instead of stacking in the middle where the record already is.

Ping-pong widens as it repeats, which is why it survives a busy mix — the echoes sit where the track is not.

Tape echo

Tape echo is a delay modelled on a tape machine: each repeat comes back darker, slightly unstable in pitch and a little saturated. It degrades as it repeats rather than copying cleanly.

Each repeat loses top end, so a tape echo can run long without ever competing with the record coming in.

Phaser

A phaser sweeps a set of notches through the frequency spectrum, cancelling thin bands as it moves. The result is a hollow whoosh that circles rather than rising, and it never quite arrives anywhere.

A phaser moves without going anywhere — use it to hold tension through a long blend, not to signal a change.

Flanger

A flanger mixes a signal with a copy of itself delayed by a few milliseconds, and moves that delay. The interference produces a metallic jet-engine sweep — the same idea as a phaser, far more aggressive.

A flanger is the aggressive cousin of the phaser: a few milliseconds of delay, swept, and it eats the top end.

Bit crusher

A bit crusher throws away digital resolution on purpose — fewer bits of level, a lower sample rate, or both. The result is gritty aliased distortion that gets harsher the further you push it.

A bit crusher is a one-way door — ride it in and out across a bar rather than leaving it sitting on a record.

Pitch shifter

A pitch shifter moves a track up or down in pitch without changing its tempo. It is what key lock does continuously, exposed as an effect you can push in whole semitones.

One semitone of shift moves a track seven positions round the Camelot wheel — that is a key change, not a tweak.

Noise FX

Noise FX add broadband hiss, usually filtered and swept, on top of whatever is playing. They cover a transition rather than shaping it, filling the join with sound the ear is willing to accept.

Noise covers a join the ear would otherwise hear — it hides a bad edit, and it hides a good one just as well.

Beat FX

Beat FX are the effects section on a DJ mixer that locks its timing to the detected tempo. Every delay, echo, roll and gate is set in beat divisions rather than in milliseconds, so one setting stays musical across records.

Beat FX are only as accurate as the tempo they read — a wrong BPM puts every division fractionally off the grid.

Colour FX

Colour FX are the per-channel effects on the knob above each channel — filter, noise, crush, echo. Centred is off; turning either way engages the effect on that deck alone.

The colour knob is per channel, so it is the only effect you can put on one record without touching the other.

Send and return

A send takes a copy of a signal to an external effect; the return brings the processed version back into the mix. The original keeps playing, so the effect is added alongside rather than replacing it.

A send leaves the dry track playing, which is why an effect on a send can never make a record disappear.

Wet/dry

Wet is the processed signal, dry is the untouched original. The wet/dry control sets how much of each you hear, and on most DJ effects it is the only depth control there is.

Ride the wet control rather than switching an effect on: an effect that arrives is a move, one that appears is a mistake.

Saturation

Saturation adds harmonics by pushing a signal into gentle distortion. It makes a sound feel louder and denser without the meter moving much, which is why almost every commercial master has some.

Saturation buys perceived loudness without level — which is exactly why it hides from the meter you gain-match on.

Gate

A gate mutes a signal whenever it falls below a set threshold, so only the loud parts get through. It is the mirror of a compressor: one works on what is loud, the other on what is quiet.

A gate keeps the hit and loses the room around it — set the threshold by ear, then check it on the quiet passages.

Intro

The intro is the stretch at the start of a track built for mixing — usually drums and little else, running a fixed number of bars so an incoming record can be beatmatched and blended before anything melodic arrives.

On all 63 records we hold as both an extended mix and a radio edit, the extended cut is the longer one — by a median of 48 seconds, which at 128 BPM is 25.6 bars.

Outro

The outro is the stretch at the end of a track built for mixing out — the arrangement thinned back towards drums so the next record can come up underneath it without two vocals or two basslines colliding.

Count an outro in bars, never in seconds — 32 bars is a fixed amount of music and a shrinking number of seconds as the set speeds up.

Breakdown

A breakdown is the section where the drums fall away and the track opens out — pads, vocal, atmosphere — before the beat returns. It is the natural place to mix into, because there is very little left to clash with.

A breakdown is a hole in the arrangement, and a hole is exactly what a transition needs.

Build-up

A build-up is the climb out of a breakdown — a riser, a snare roll, filters opening — that tells a floor the drop is coming. It is arranged to land exactly on a phrase boundary rather than wherever it happens to finish.

A build-up points at one exact moment, so finish the transition before it starts or wait until after the drop.

Drop

The drop is the moment the full arrangement lands after a breakdown — beat, bass and hook arriving together. In most club records it is the point the whole track is arranged around, and the thing a floor is waiting for.

The drop is the one moment in a record where you have no room — mix before it or after it, almost never across it.

Hook

The hook is the part of a record people remember — the vocal line, the riff, the moment that makes it that track rather than any other. Everything else in the arrangement exists to set it up.

Mix around the hook, never across it — the room is following it, and two at once is the most obvious mistake you can make.

Riser

A riser is a sound that climbs in pitch or volume through a build-up, signalling that something is about to land. White noise, a filtered sweep or a rolling snare all do the job.

A riser is a countdown the whole room can hear, so treat it as a deadline for finishing whatever you started.

Sweep

A sweep moves a filter across a sound so its brightness travels — up towards a moment or down away from one. It works as an arrangement element inside a track and as a live move on a mixer.

A sweep announces itself, so spend it where you want the room to look — not on every transition.

Extended mix

An extended mix is the DJ cut of a release — a longer intro and outro with more bars of beats at each end, so there is room to mix in and out. It is the version that belongs in a set.

56,070 of 443,414 titles with a duration (12.6%) say "Extended Mix", and they run to a median of 5:23 — slightly shorter than the 5:48 median of the catalog around them.

Radio edit

A radio edit is a shortened version cut for airplay — usually under four minutes, with the long intro and outro removed and the arrangement tightened. It is the version that gives a DJ the least to work with.

Only 803 of 443,414 titles with a duration (0.18%) say "Radio Edit", and they run to a median of 3:30 against 5:48 for the catalog — 2 minutes shorter.

Remix

A remix is a new production built from another artist’s parts — usually a different arrangement, often a different genre and tempo. The original vocal or hook survives; almost nothing else has to.

50,945 of 443,414 titles with a duration (11.5%) are remixes, and they run longer than the catalog they sit in — a median of 6:19 against 5:48.

VIP

A VIP — Variation In Production — is the producer’s own rebuild of their own track, usually made for their own sets. It is not a remix: same artist, same record, a different arrangement built to land harder.

1,431 titles in the catalog carry a VIP marker, and they run to a median of 4:18 — 1:30 shorter than the catalog’s 5:48.

Dub

A dub is a mix with the vocal stripped back or removed and the rhythm section pushed forward. It leaves long, sparse stretches to mix over, which is why the dub is so often the DJ-friendly cut of a release.

The 717 dub titles in the catalog run to a median of 6:10 — longer than the extended mixes at 5:23 and longer than the catalog as a whole at 5:48.

Bootleg

A bootleg is an unofficial edit or remix released without the rights holder’s permission. It circulates on USB sticks and private links rather than through stores, which is exactly why you will not find many for sale.

19 titles in a catalog of 443,414 carry a bootleg marker — roughly one in 23,000 — because a licensed store is the last place a bootleg can be sold.

Acapella

An acapella is a vocal with no instrumental behind it, released so DJs and producers can lay it over another record. It is the raw material for a mashup, and it is rarely sold alongside the tracks it came from.

7 titles in 443,460 carry an acapella marker. A licensed store catalog is not where acapellas live, and that number is the clearest way we can say so.

Edit

An edit is a rearranged version of an existing record — a longer intro, a trimmed breakdown, a drop moved — made by a DJ for their own sets. The original parts stay; the running order changes.

2,302 titles in the catalog are edits rather than radio edits — against 50,945 remixes, because most edits are never cleared.

Stems

Stems are the separated parts of a record — drums, bass, vocal, melody — as individual audio files. Modern players and software also generate them live from a finished stereo track.

Live separation removes a part; an EQ removes a frequency range — that is the whole difference.

Dubplate

A dubplate is a one-off record cut for a single DJ, historically onto acetate. In sound-system culture it is usually a personalised version of a track recorded specially for that DJ.

A dubplate is a record only you can play — the format changed, the exclusivity is the point.

White label

A white label is a record pressed with a blank or minimal label, sent out ahead of release or issued without official credits. It carries no artwork and often no artist name at all.

A white label arrives with no metadata — whatever you type in is all your library will ever know.

Track ID

A track ID is a request to name a record played in a set — and, in a tracklist, the placeholder "ID" standing in for a track that is unreleased or deliberately withheld.

An ID in a tracklist means the record is unreleased or withheld — not that the DJ forgot it.

Sync

Sync matches one deck’s tempo to the other automatically and holds it there, using the beatgrid the software calculated. It removes the arithmetic of beatmatching, not the decision about which record follows which.

Across 7,254 hand-sequenced transitions the median tempo correction is 0.83% — and on 27.4% of them there is nothing to correct.

Quantize

Quantize snaps your actions to the beatgrid: a cue point, a loop or a hot cue fires on the next grid line rather than the instant your finger lands. The setting decides how coarse that grid line is.

Set quantize to 1 beat for cue and loop work, and turn it off when you want to place something by hand.

Slip mode

Slip mode keeps the track running silently underneath whatever you are doing to it. When you release a loop, a scratch or a reverse, playback jumps to where the record would have been if you had never touched it.

Slip lets you loop, reverse or scratch over a mix and land back in phrase, because the track never actually stopped.

Loop roll

A loop roll repeats a short slice of the track — usually a beat or less — while the record keeps running underneath. Release it and playback continues from where it would have been, so nothing is lost.

Roll the last bar before a drop, halving the length as you go: 1 beat, then 1/2, then 1/4, released on the downbeat.

Hot cue

A hot cue is a saved position in a track that plays from that point the instant you press its pad. Most players store eight per track, and they are stored with the file rather than with the session.

Three cues cover most records: the first beat of the intro, the drop, and the bar the outro starts.

Memory cue

A memory cue is a saved marker you navigate to rather than trigger. It appears on the waveform and the player jumps to it when you call it up, without playing until you tell it to.

Use memory cues as the map of a record and hot cues as the controls you press.

Performance pads

Performance pads are the grid of rubber buttons on a controller or player. Each pad mode reassigns the whole grid to a different job — hot cues, loop rolls, slicing, samples or beat jumps.

Pick two pad modes and stay in them: hot cues for navigation, rolls for tension. The rest are for records you know.

Waveform

The waveform is the picture of a track’s level over time, usually coloured by frequency content. It is how DJs read a record’s shape without listening to it — where it thins out, where it lands, where it ends.

How tall a track draws is only loosely related to how hard it hits: loudness and analysed energy correlate at 0.32 across 443,242 tracks.

Beatgrid drift

Beatgrid drift is a grid that lines up at the start of a track and slides out of alignment later — the tempo the software stored is close to the real one but not equal to it.

Where our two tempo readings of a file disagree by more than 2 BPM, 54.8% are out by a musical ratio — double, 4:3 or 3:2.

Pitch bend

Pitch bend is a momentary speed change used to correct phase — nudging the jog wheel or holding a bend button to push a track forward or drag it back without altering its tempo setting.

Bend to fix where a track is, not how fast it runs — a touch on the platter, released the moment the kicks agree.

Needle drop

A needle drop is starting a track at a chosen point with no blend at all — dropping straight in on a downbeat, named for placing a stylus onto a moving record.

Drop on the first beat of a phrase with the outgoing track cut on the same beat — no overlap, no fade, no apology.

CDJ

A CDJ is the club-standard media player: a jog wheel, a pitch fader, hot cues and a waveform display, playing from a USB stick, an SD card or a laptop. It carries no mixer of its own.

Two players and a mixer is the layout every club has, which is the argument for rehearsing on it.

Standalone player

A standalone player reads music straight from a USB stick or SD card. The decoding, the display and the cueing all happen inside the player, so nothing about the performance depends on a computer being awake.

Carry two sticks with identical exports, and format them the way the player’s manual asks.

All-in-one system

An all-in-one system puts two or four decks and a mixer in a single chassis and plays from USB with no laptop. It replaces a pair of players plus a separate mixer with one box and one power lead.

It buys the standalone workflow in one box, and costs you the layout a club booth actually has.

Controller

A controller is a jog-wheel-and-mixer surface that drives DJ software on a computer. It sends control messages rather than making playback decisions, and usually carries the soundcard that turns the software’s output back into sound.

The laptop is the instrument and the controller is the surface, so protect the laptop first.

Pro DJ Link

Pro DJ Link is the Ethernet network that joins several players and a mixer. One USB stick feeds every deck, the players share tempo and beat position, and lighting or recording software can read the whole rig from one connection.

One stick feeds every deck, and one bad Ethernet cable takes a player off the network silently.

DVS

A DVS — digital vinyl system — plays software tracks from real turntables or CD decks. A control record carries a timecode signal, an interface digitises it, and the software follows the position and speed of the platter.

When a DVS misbehaves, suspect the needle and the earth before you suspect the software.

Timecode vinyl

Timecode vinyl is a record pressed with a control signal instead of music. DVS software reads that signal to work out where the needle sits and how fast the platter is turning, then plays a digital track to match.

Flip the record when playback gets erratic — a worn side reads as a software fault and is not one.

Slipmat

A slipmat is a felt disc between the turntable platter and the record. It lets the platter keep spinning while you hold, drag or pull back the record itself, which is what makes cueing and scratching possible.

A mat that grabs is a worn or damp mat — replace it before you adjust anything on the deck.

Crossfader

The crossfader is the horizontal fader that blends between two channels. At one end you hear only the left assignment, at the other only the right, and a curve control sets how abruptly the handover happens in between.

Check the assign switches before you blame the deck — a channel assigned to the wrong side is silent.

Channel fader

A channel fader is the vertical level control for one deck. The crossfader chooses between two sources; the channel faders decide how much of each is in the room, which is where most club mixing actually happens.

Set the level with the gain, then use the fader for the move — never the other way round.

Rotary mixer

A rotary mixer replaces channel faders with knobs. It usually has no crossfader, an isolator-style EQ and a deliberately unhurried response — the design assumes long blends rather than cuts, and the format encourages them.

On a rotary you blend rather than cut, and the bass swap does the work a fader does elsewhere.

Isolator

An isolator is a three-band EQ that removes a band completely rather than attenuating it. Where a standard mixer EQ bottoms out around −26 dB, an isolator goes to silence, which makes a bass swap absolute rather than gradual.

A true kill makes the bass swap one decisive move; a −26 dB cut lets you blend the handover instead.

Pre-fade listen

Pre-fade listen sends a channel to your headphones before its fader is up, so you hear the next track while the room hears only what is already playing. It is what the cue button on every mixer does.

Only 1,428 of 7,250 transitions DJs build here arrive with tempo, level and key already matched; the rest is what the headphones are for.

Cue mix

The cue mix knob sets the balance in your headphones between the cued channel and the master output. Fully one way you hear only the track you are lining up; fully the other, only what the room is hearing.

Sit near the middle and let the room push you towards cue — the master is already reaching your ears.

Split cue

Split cue makes the headphones mono and sends the cued channel to one ear and the master to the other. You lose the stereo image and gain clean separation between the track you are cueing and the one playing.

Use it when the room is too loud to hear drift in a blend, and switch back when it is not.

Booth monitor

The booth monitor is the speaker pointed at the DJ, fed from its own output with its own level control. It is separate from the master, so turning it up changes what you hear and nothing the room hears.

Set the booth once, early, and reach for the booth knob rather than the master for the rest of the night.

MIDI

MIDI is the control language a controller speaks. It carries note and control-change messages rather than audio, each with a value from 0 to 127, which is how a knob movement becomes a parameter change in software.

A standard MIDI control has 128 steps across its whole travel, which is why some faders feel coarse.

MIDI mapping

MIDI mapping assigns a physical control to a software function. Most software has a learn mode: arm mapping, move the knob, click the function, and that control drives it until you change it again.

Export the map the day it works, and turn on soft takeover before you map a single knob.

Audio interface

An audio interface converts between the digital signal inside software and the analogue signal a mixer or amplifier accepts. In a timecode rig it also converts the other way, digitising the control signal coming off the turntables.

Raise the buffer until the dropouts stop, then stop — every increase is delay you will feel.

Line level

Line level is the standard signal strength equipment sends between devices — a player into a mixer, a mixer into an amplifier. It is far stronger than a microphone or turntable signal, which need preamplifying first.

Wrong input setting, not wrong gain: a player into phono distorts at every setting on the knob.

Ground loop

A ground loop is a hum caused by two pieces of connected equipment being earthed at different points, so current flows through the audio cable's shield. It sounds like a steady low buzz at mains frequency.

A steady hum that appears only when two devices are connected is a ground loop, not a faulty cable.

Balanced and unbalanced

A balanced connection carries the signal twice, once inverted, and cancels anything picked up along the way. An unbalanced one carries it a single time, so interference picked up by the cable stays in the signal.

Balanced cancels what the cable picks up, so it only matters on the long run out of the booth.

Phantom power

Phantom power is 48 volts sent up a balanced microphone cable by a mixer or interface to power a condenser microphone. It is switched on at the input, and most DJ equipment does not provide it.

A condenser mic needs 48V and most DJ mixers do not have it — bring a dynamic instead.

RCA and XLR

RCA is the unbalanced two-channel connector on players, turntables and consumer gear. XLR is the balanced three-pin connector used for long runs and microphones, and it locks into place.

RCA pulls out when somebody catches it; XLR locks — which is why the long run uses XLR.

Scratch

A scratch is a sound made by moving a record back and forth under the needle while the crossfader or channel fader cuts it in and out. The hand sets the pitch; the fader sets the rhythm.

Every named scratch is two hands doing different things — the record sets pitch, the fader sets rhythm.

Baby scratch

The baby scratch is the first one anyone learns: push the record forward and pull it back in time with the beat, fader open throughout. No fader work at all — only the hand.

Push and pull to the beat with the fader open — get this in time before adding any fader at all.

Forward scratch

A forward scratch is a baby scratch with the return silenced: push the record forward with the fader open, then close the fader before pulling it back. Only the forward half is heard.

Close the fader on the way back and the scratch becomes a stab you can drop into a running mix.

Chirp scratch

A chirp starts with the fader open and closes it at the end of the forward push, then opens it partway through the pull back. Cutting off the tail of each motion is what makes the sound.

Cut the tail off both halves — the fader has to land mid-motion, not between motions.

Transformer scratch

A transformer scratch keeps the record moving slowly and steadily while the fader is stabbed open and shut, chopping one continuous sound into rhythmic bursts. The fader does all the work.

Hold a slow, even record motion and put the whole rhythm in the fader — this is a fader exercise.

Flare scratch

A flare starts with the fader open and clicks it shut one or more times mid-motion, so the sound is interrupted rather than started. One click is a one-click flare, two is a two-click.

The fader starts open and clicks shut mid-motion, so a missed click still leaves you with a sound.

Crab scratch

A crab is a flare played with the fingers rather than the thumb: the thumb holds tension against the fader while four fingers release it one after another, giving four clicks in one motion.

The thumb pushes back, four fingers release one at a time — four clicks in a single record motion.

Scribble scratch

A scribble is a fast tremble of the record made from the forearm rather than the wrist, with the fader left open. It produces a dense burst rather than an articulated pattern.

Tense the forearm and let it shake — this one is a texture you place, not a rhythm you count.

Hamster crossfader

Hamster is a crossfader wired in reverse, so the left deck lives on the right side of the fader. Scratch DJs run it because it puts the cut on the pull rather than the push.

Flip it, learn one orientation, and switch it back before anyone else plays on that mixer.

Backspin

A backspin is the record pulled sharply backwards while the platter keeps turning underneath, throwing the track back through itself. It is used as an effect mid-phrase and as a way out of a track.

The platter keeps spinning under the felt, which is why the track returns at pitch the moment you release.

Spinback

A spinback ends a track by throwing it backwards out of the mix — by hand on a platter, or with the reverse and brake controls on a player that has none. No beatmatching required.

606 of 7,254 transitions DJs sequence here join two records no pitch fader can bring together — an exit, not a blend.

Brake

A brake is a controlled slowdown to a stop, either by killing the turntable motor or with the brake control on a player. The pitch falls with the tempo, which is the whole effect.

The brake time is the whole effect — a quarter-bar reads as a stutter, two bars as a power cut.

Reload

A reload is pulling a track back to its start and dropping it again, usually seconds after the moment the crowd reacted to. It is native to jungle, drum and bass, garage and dubstep.

A reload answers a reaction that already happened — if the room did not move, do not pull it back.

Vinyl simulation

Vinyl simulation is the setting that makes a jog wheel behave like a platter: touching the top stops the track, the side nudges it, and releasing lets it spin back up to speed.

With vinyl mode off, the top of the jog wheel only bends pitch — nothing you do will produce a cut.

Crate

A crate is a folder of tracks inside your DJ software, named after the boxes vinyl DJs carried. A track can sit in as many crates as you like without being copied, because a crate holds references rather than files.

Build crates around situations rather than genres: the software already knows the genre, and it does not know your rooms.

Crate digging

Crate digging is the search for records nobody has handed you — going past the charts and the promo mail into back catalogue, reissues and things filed where you were not looking.

Of the 110,237 tracks whose true first-release year we have researched, 10,237 carry a store date at least two years later — a median of 10 years later.

Playlist vs crate

A crate is a collection of tracks you might play; a playlist is a running order you intend to play. The distinction is order — a crate is a box, a playlist is a sequence.

If the order carries information, it is a playlist. If it does not, it is a crate — and mixing the two costs you both.

ID3 tags

ID3 tags are the metadata written inside an audio file — title, artist, album, genre, year, comment, and on DJ files often BPM and key. They travel with the file rather than with the software that read it.

Our catalog carries a tempo on 443,307 tracks and a key on 443,414 of 443,460 — and an ISRC, the one identifier built to survive a re-release, on zero.

Library database

Your DJ software keeps its own database of everything it knows about your collection — file locations, beatgrids, cue points, crates, play history. The audio files sit elsewhere on disk; the database is what turns them into a library.

Back up the database, not just the music — the audio is replaceable and the grids, cues and crates are not.

Duplicate detection

Duplicate detection finds the same record stored more than once — usually by comparing artist and title after normalising punctuation and case, sometimes by duration or by an identifier inside the file.

Matching on normalised artist and title, 357 groups in our catalog hold the same record twice — and dropping the version suffix finds 1,464 more.

Relinking missing files

Relinking points your library’s database back at audio it can no longer find, after the files were moved, renamed or unplugged. The track entry survives with its grids and cues; only the path to the audio is broken.

Relink, never re-import: the entry still holds your grids and cues, and re-adding the file throws them away.

Comment field

The comment field is free text inside an audio file, and the only metadata slot nobody else is using. DJs fill it with the things no other field holds — energy ratings, where a record works, what it mixes into.

Use short fixed codes, not sentences: an energy number, a situation, and where it goes next.

Tag

A tag is a label you attach to a track so you can find it by something other than its name — a genre, a mood, a situation. A track can carry as many as you like.

The catalog runs to 168 genre tags, but 395,353 of 443,460 tracks carry exactly one — a store files a record in a single place.

Cue sheet

A cue sheet is a small text file listing what plays when inside one long audio recording — track titles, artists and start times. It is how a recorded mix is split into a tracklist without being cut into separate files.

Write the cue sheet from the recording, not from memory: the times are the part you will get wrong.

USB prep

USB prep is exporting the tracks, grids, cue points and playlists you need onto a drive a club player can read. What is not exported does not exist once you are behind the decks.

Export twice, onto two drives, and test one in a player before you leave — not in the software that wrote it.

Set list

A set list is the running order a DJ intends to play — the sequence rather than the collection. How long it needs to be is arithmetic: slot length divided by how long the records actually run.

The median track in our catalog runs 5:48, so a two-hour set played back to back is about 21 records — and half that again is a sensible list.

M3U playlist

An M3U is a plain text file listing paths to audio files in order. Almost every application can read one, which makes it the lowest common denominator for moving a running order between programs.

Use M3U to hand an order to another program, and expect nothing else to travel with it.

Sample rate

Sample rate is how many times a second a digital file measures the waveform, in kilohertz. CD audio is 44.1 kHz, and the number sets the highest frequency the file is able to carry.

44.1 kHz already covers everything a human hears — higher rates buy production headroom, not a better club file.

Bit rate

Bit rate is how much data one second of audio uses, in kilobits per second. It decides the file size, and on a lossy format it decides how much of the original recording survives the encoding.

The median track here runs 5:48, which is 61.4 MB as a WAV and 13.9 MB at 320 kbps — about 2,298 tracks on a 32 GB drive, against 521.

FLAC

FLAC is a lossless compressed format: it shrinks a file without discarding any audio, so decoding returns the original samples exactly. It typically lands around 60% the size of the WAV it came from.

FLAC is the same audio as the WAV in about 60% of the space — the cost is player support, not sound.

WAV and AIFF

WAV and AIFF are uncompressed audio containers — the raw samples, no encoding. They sound identical to each other and differ mainly in how they store tags and which software wrote them.

WAV and AIFF are the same audio in different wrappers — pick the one your software tags reliably.

AAC and M4A

AAC is a lossy codec, usually delivered in an .m4a container, and it is what Apple’s ecosystem and most video use. At the same bit rate it generally holds up better than MP3.

AAC beats MP3 at the same bit rate — the reason to prefer MP3 anyway is that every club player reads it.

Lossless

Lossless means the encoding discards nothing: decode the file and the original samples come back bit for bit. WAV, AIFF, FLAC and ALAC are lossless; MP3 and AAC are not.

Buy lossless and convert down when you need to — you cannot get back what a lossy encoder threw away.

Lossy compression

Lossy compression shrinks a file by discarding audio a listener is unlikely to notice. What it removes is gone permanently, and encoding an already-lossy file removes more on top.

Every re-encode removes more, and none of it comes back — keep one lossless master and generate the rest from it.

Record pool

A record pool is a subscription service supplying DJs with promotional music, usually including edits, intro versions and clean radio cuts that are not sold anywhere else.

A pool ships the versions stores do not sell — and enough volume to bury a library if you let it.

Peak time

Peak time is the stretch of a night a set is built toward — the busiest hour, and the point of highest energy. It names a position in a night rather than a specific sound.

The genre tag named for it is not the hardest music in the catalog: Techno (Peak Time / Driving) holds 24,997 tracks at a mean energy of 66, 6th of the 33 genre tags with 4,000 or more analysed tracks.

Warm-up

A warm-up is the opening stretch of a night — slower, quieter, and built to leave the next DJ somewhere to go. Playing peak-time records in a warm-up is the oldest mistake in the job.

Opening tracks in the 518 sets built here average 55 for energy against 63 in the closing third — DJs really do start low and climb.

Closing set

A closing set is the last stretch of a night, played after the peak has passed. Its job is to land the room rather than lift it, which is why closers are rarely the hardest records of the night.

Across 518 sets sequenced by hand here, the closing track averages 61.7 on energy against 63.2 for the last third before it — sets peak before they end, not at the end.

Energy curve

An energy curve is the shape a set makes over time — where it starts, how steeply it climbs, where it peaks. It is the plan behind a running order, and the thing a crowd feels without being able to name.

Hand-sequenced sets climb 55.0 → 57.3 → 60.7 → 63.2 across their opening, first, middle and last thirds, then step back to 61.7 on the closing track.

Trainwreck

A trainwreck is a transition that falls apart in public — beats drifting out of phase, two basslines fighting, the floor noticing. Every DJ has had one, and most of them start with tempo rather than with key.

Only 5.05% of 7,243 hand-sequenced transitions jump more than 20 BPM. The median gap is 1.0 BPM and 81.5% land within 3.

Transition

A transition is the move from one track to the next — the overlap where both are playing and the point where the first is gone. It is the unit a set is actually built from, rather than the tracks themselves.

We hold 96,963 measured pairings across 12,354 artists and 5,622 community-rated transitions, on top of 7,243 sequenced by hand here.

Blend

A blend is a transition where both records play together for a stretch — long enough that the overlap is part of the music rather than a join between two pieces of it.

Across 7,243 transitions sequenced by hand here, the median energy gap between adjacent tracks is 4 points on a 100-point scale — DJs blend into records that feel almost identical.

Cut

A cut swaps one record for another on a single beat, with no overlap. It is the fastest transition there is and the only one that works between two records with nothing in common.

A cut needs only one thing to be right — the beat it lands on. That is what makes it the move for incompatible records.

Double drop

A double drop lands the drops of two records at the same instant. Done right it is the biggest moment a DJ can manufacture; done wrong there is no way to hide it.

Both drops have to land on the same bar, at the same tempo, in compatible keys — and there is no partial version to retreat into.

Back-to-back

A back-to-back set is two or more DJs alternating tracks on the same system. Each plays into whatever the other left, so nobody controls the direction of the set on their own.

The 7,243 hand-sequenced transitions we measure come from 716 sets built by 515 different DJs — and 70.5% of their moves are textbook Camelot, against 18.3% by chance.

Doubles

Playing doubles means running two copies of the same record at once, offset or in sync. It is used to extend a section, to loop a passage live, or to juggle a phrase between decks.

Two copies offset by a phrase let you hold one section indefinitely — cut back before it ends and it never resolves.

Echo out

An echo out ends a record by feeding its last bars into a delay and pulling the channel down, so the track dissolves into repeats instead of stopping.

An echo out manufactures an outro for a record that never had one — and covers a transition between two tracks with nothing in common.

Open format

An open format DJ plays across genres in one set — hip-hop into house, disco into garage — rather than staying inside a single style. The joins are made on tempo, energy and key instead of on genre.

457 of 717 sets built here cross a genre boundary at least once — open format is the majority case, not a niche.

Set time

Set time is the length of the slot a DJ is booked for — the number that decides everything else about the set, from how many records fit to how fast the energy can move.

The median set built here runs 41.1 minutes across 9 tracks — a warm-up slot, not a headline one.

All night long

An all night long set is one DJ playing the entire night — opening the room, taking it through peak time and closing it — with no other DJ on the bill.

The discipline is at the front — anything that would win an hour makes hour five impossible.

Headliner

The headliner is the billed act a night is sold on, playing the slot the room is fullest for — usually peak time rather than the last set of the night.

The headline slot is where the room is fullest, which is rarely the last set of the night.

Residency

A residency is a regular booking at one venue — weekly, monthly or seasonal — where the same DJ plays often enough that the room, the sound system and the crowd become familiar.

A residency lets you introduce a record in June and have the room recognise it in September.

Promoter

A promoter books the acts, hires the room, sells the tickets and carries the financial risk of a night. They decide who plays, in what order, and for how long.

Answer with what you can cover, not what you want — the slot on offer is usually a budget decision.

Soundcheck

A soundcheck is the time before doors to test your setup through the venue system — levels, monitoring, connections — so that nothing is discovered for the first time in front of a room.

Check the connections and the monitor, not the sound — an empty room tells you nothing about a full one.

Green room

The green room is the space set aside for artists at a venue — somewhere to wait, store equipment, and be away from the floor before and after a set.

It is where your bag is safe and where the DJ coming off gets ten minutes — treat it as both.

Rider

A rider is the document setting out what a DJ needs to perform — the technical rider lists equipment and setup, the hospitality rider covers travel, accommodation and the practical side.

List only what would stop the set — a rider naming two essentials gets read, one naming twenty gets skimmed.

EPK

An EPK is an electronic press kit — a single page or file holding a DJ's bio, photos, mixes, links and contact details, sent to promoters and press instead of a scattered set of messages.

A promoter wants a mix, a photo and a line to paste — anything they have to ask for is friction.