5.6. BPM Matching and Allowances

Same Mix BPM compares rounded whole BPMs within the allowances below. Tracks keep their original playback speed and keys. The Mix table displays the rounded BPM, with the detected decimal available in the tooltip.

Same Mix BPM + pitch shifts also allows speed changes in the selected semitone range. Choose +/-1 semitone or +/-2 semitones directly under Pitch range; the second choice includes one-semitone changes too. Each track uses the allowed adjustment that brings its rounded effective BPM closest to the Mix target; equally close choices prefer less pitch change. Rounded playback ratios must remain within five cents of the selected semitone step. Keys shift with playback before Allowed Keys and transition matching are evaluated.

Same Mix BPM + keylock uses the same two BPM allowances as Same Mix BPM, comparing each track’s original rounded tempo before keylock. Eligible native-ratio tracks are planned for playback at the Mix BPM while preserving their original keys; half/double-time matches use the corresponding physical deck tempo shown in the tooltip. HDJ previews at the original speed and key, so you can judge harmonic flow before performing the tempo changes in your DJ software. The Mix table shows the authoritative BPM used to derive the comparison, with keylock underneath; its tooltip identifies the planned tempo.

Include half/double-time tracks is available with every Same Mix BPM strategy and is off by default. It also compares each authoritative rounded track BPM at twice and half its value, so a 61 BPM track can match a 122 BPM Mix as half-time and a 244 BPM track can match it as double-time. The selected relationship is contextual to this Mix target: Harmonic DJ does not relabel the track, rewrite its BPM, or change playback speed merely because of the ratio. With pitch shifts, only the independently selected semitone adjustment changes audition speed and key. With keylock, the tooltip shows both the physical planned tempo and its Mix-BPM equivalent.

Same Mix BPM and Same Mix BPM + keylock both apply the sliders to original rounded BPM after any enabled target-relative normalization. Same Mix BPM + pitch shifts applies them after normalization and the selected pitch shift: a 120 BPM track shifted to 127 BPM and an unshifted 127 BPM track have zero effective BPM difference. In keylock mode, those tracks retain their original 7 BPM gap for selection, so a Between tracks allowance of 3 rejects the pair even when both could eventually play at the Mix BPM.

From Mix BPM allows each track to sit above or below the Mix target by up to 12 BPM. Between tracks allows consecutive tracks to differ by up to 3 BPM. For example, at Mix BPM 128, an overall allowance of 4 admits effective tempos from 124 through 132, while a between-track allowance of 2 requires smaller steps through that range.

The sliders are linear and move in whole BPM steps. Both start at 0, meaning an exact rounded match. Values stay in fixed positions with no decimal places. A drag creates one undoable change; double-clicking restores zero.

Ignore BPM leaves playback unchanged and matches keys without requiring detected BPM. The half/double-time toggle and both allowances are hidden and ignored in this mode; their saved values return when any Same Mix BPM mode is selected. The two Pitch range choices appear only in pitch-shift mode. Switching modes retains the selected half/double-time choice, pitch range, and both BPM allowances. Reset Mix Settings turns the ratio option off, and older Mix documents without the field load with it off.

Allowances include their boundaries and apply to generation, same-key replacements, and Gem Finder. Locks and saved Gems cannot bypass them during planning. Changing allowances keeps authored rows and their original transition explanations, while incompatible rows show BPM limit with details in their tooltips. Allowances, reset, undo, and redo are saved with the Mix.

For keylocked performance, enable keylock in your DJ software. An exported M3U playlist carries track order and audio paths; it does not set deck keylock or tempo. HDJ’s keylock previews stay at the original tempo, while pitch-shift previews change speed and pitch together.