Mixing from 9B to 9A

How to mix this transition

Since 9B and 9A share a key signature, you can layer the incoming E Minor track over the tail of the G Major groove for 8–16 bars before fully committing. Use a high-pass filter on the outgoing track to thin its presence as the new one enters, letting the minor tonality emerge without collision. Bring in the new track at a phrase boundary in the outgoing tune—typically after an 8 or 16-bar section—so the modal flip lands on a structural downbeat rather than mid-phrase. The main pitfall is holding both tracks at full EQ simultaneously; the relative relationship only works if you actively carve space for the minor tonality to breathe.