Library & files
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.
In practice
Back up the database, not just the music — the audio is replaceable and the grids, cues and crates are not.
Do file moves from inside the software, never from the desktop, and export a collection backup before any large reorganisation or version upgrade. Keep the audio in one tree with a shape you can live with for years, because the shape is what the database has recorded. If you work across two machines, treat one as the master and sync in one direction — two databases both editing the same tree is how the same track ends up with two sets of cue points.
The database
What to back up
Inside the app
Where to move files
One master
If you use two machines
Where these come from: Library-management practice across Rekordbox, Serato, Traktor and Engine DJ — not catalog figures. Each stores its collection differently and none of them read another’s. For what we can measure, see what happens when the paths break.
Why it matters
Everything you have ever prepared lives in that one file, and almost nobody backs it up. Losing it does not lose the music, which is the trap: the collection still plays, and every grid, cue and crate you built is gone.
It also explains the single most common library disaster. Moving or renaming files in Finder or Explorer does not tell the database anything, so a tidy-up outside the software is how a working collection becomes a screen of missing tracks.
In Mixgraph
Mixgraph reads an exported library and never writes to it — nothing we do can move, rename, retag or delete a file.
Frequently asked
Where does Rekordbox store its library?+
In its own database file alongside your collection, separate from the audio. That database holds the beatgrids, cue points, crates and play history — everything you prepared, and nothing you can re-download.
What happens if I move my music files?+
The database keeps pointing at the old paths, so the tracks show as missing and need relinking. Moving files from inside the software updates the paths as it goes.
Should I back up my DJ library?+
The database especially. Losing the audio costs money; losing the database costs every grid, cue point and crate you have built, which is the part you cannot buy again.
Related terms
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.
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.
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.
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.