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Section 1Rus

Tempo-map synchronization when processing a full track (Full Mix)

Example files: Drums MIDI (full mix result)

When you upload a full mix to DrumsMIDI, the service returns:

  • a MIDI file of the drum part (example_full_mix.mid) — with a tempo-map already embedded, calculated by our service from your audio;
  • an archive with stems (stems.zip) — separate tracks (vocals, bass, drums, guitar, piano, other) extracted from the mix.

This section shows how to open the MIDI correctly, make sure it lines up exactly with your track, and remove the silence at the start.

1.1. Correct tempo-map import — by opening the MIDI file

The key point: do not drag the MIDI into an already open project — Logic will then fit it to the project tempo (120 BPM) and break the grid. Instead, open the MIDI file itself as a new project — then Logic will take the tempo-map straight from the file.

  1. In Finder, right-click example_full_mix.mid → Open With → Logic Pro.
  2. Logic creates a new project where:
    • the Tempo track is filled with the tempo-map from the MIDI (varying tempo, you can see the bends in the tempo curve);
    • an instrument track for the drums (SoCal) with a Drums region appears;
    • in the Piano Roll (the section at the bottom of the screen) the part is laid out as notes, where Kick = C1.

1.2. Checking that the MIDI matches the source audio

Now you need to make sure the drum notes land exactly on the hits in the audio.

  1. Check the source file's parameters: right-click the .wav → Get Info. Make sure it's the right file (e.g. Sample rate 44.1 kHz, Stereo).
  2. If the project's sample rate doesn't match the audio's sample rate, set the project's sample rate to that of the audio.
  3. Drag the source audio (or the stems) into the project and place it at the very start — position 1 1 1 1.
  4. In the Add Selected Files to Tracks dialog, choose Create new tracks.
  5. Now the audio tracks sit next to the MIDI drums in the project.
  6. Check the alignment at several points, matching the Kick/Snare notes to the hits on the waveform:
    • the first hit at the start of the track;
    • the last hit at the end of the track;
    • a hit in the middle of the track.

If the notes land on the hits along the whole length — the synchronization between the produced MIDI and the source audio is correct.

A difference of up to 10 ms between a hit's transient and the note's start is acceptable — the processing rate is 100 FPS. A more detailed demonstration of this is in Section 2.

1.3. Removing the silence at the start

There's often silence / a pickup at the start of a track before the first hit. It's convenient to cut it from all tracks at once, together with the tempo-map, so the music starts from the first bar.

  1. Select the empty section at the start (up to the first hit) with the locators.
  2. Edit → Cut/Insert Time → Cut Section Between Locators (⌃⌘X).
  3. The silence is cut from the audio, MIDI, and tempo-map at once — the track starts from the first bar, and the tempo-map stays correct.

Note: per the Red Book (CD-DA) standard, around 200 ms of silence is left at the start of a track.

When building the tempo-map, our system tries to fit this silence into a separate first bar, to keep it apart from the actual composition. But to fit these ~200 ms into a separate first bar, the DAW has to push the tempo up to ~900 BPM — such a spike breaks the tempo curve and makes the tempo-map unreadable.

That's why, while working on the project, it's better to cut the leading silence completely — then the tempo-map stays clean and readable. Later, at the final stage when preparing for production, you can add the 200 ms of silence back to the start if you wish.

The exception is Cubase: it's limited to 360 BPM and doesn't support such a high tempo for the lead-in. For tempo-map compatibility with Cubase, tick the "DAW Cubase" checkbox in the main form during conversion.

1.4. Adapting the drums-MIDI tempo-map to the project's tempo-map

If you don't want to use the tempo-map that DrumsMIDI produced (for example, your project is at 136 BPM while DrumsMIDI produced a multiple of it, 68), or you need to insert this MIDI drum part into an already existing project with its own tempo-map, go to Section 3 "Adapting the tempo-map to a reference" — it shows how to re-grid the finished MIDI onto your project's grid using the Adjust Tempo-Map utility.