7.5. BPM, Pitch, and Gain

BPM is a Mix constraint rather than a reward. A track either satisfies the selected BPM policy or it does not. This prevents a harmonically strong but tempo-incompatible edge from slipping into a route through a weighted average.

Pitch-shifted playback changes speed and pitch together. Harmonic DJ transposes the track’s effective keys and harmonic evidence by the same integer-semitone step used to reach the Mix BPM.

Gain guidance is also independent from route selection. Per-track ECMA-relative gain helps neighboring tracks meet at a stable subjective level, while the common pre-limiter gain places the complete adjusted Mix near its integrated-LUFS target.