Audio to MIDI in Logic Pro

First: try Flex Pitch

Logic has audio-to-MIDI built in. For a single melody line that is already in your project, it is the quickest route:

1. Double-click the audio region to open the Audio Track Editor.
2. Click the Show/Hide Flex button and choose Flex Pitch from the Flex Mode pop-up menu.
3. Fix any wrongly detected notes in the editor, then choose Edit → Create MIDI Track from Flex Pitch Data.

Logic adds a new software instrument track under the audio track, with a MIDI region for each audio region.

When to use a converter instead

Flex Pitch is built for monophonic material — one note at a time. Come back here when:

• The part has chords. Flex Pitch tracks a single pitch, so a piano chord or a strummed guitar comes out as one line at best.
• You want to hear the MIDI against the original and adjust sensitivity, note length and cleanup before anything touches your project.
• The audio is an MP3 or a voice memo you have not imported yet, and you only want the notes.

Export a clean source from Logic

1. Solo the track you want. If you only have a full mix and are on Logic Pro 11 or later, the Stem Splitter can pull out vocals, bass, drums or other instruments first — convert the stem, not the mix.
2. Set a cycle area over four to eight bars and use File → Bounce → Project or Section, choosing a WAV (PCM) file.
3. Bypass reverb and delay on that track before bouncing if you can. Tails smear note onsets and turn into extra notes.
4. Note the project tempo in the LCD. You will need it next.

Convert

1. Drop the WAV into the audio to MIDI converter. It runs in your browser, so nothing is uploaded.
2. Select the section you want — up to sixty seconds per run.
3. Play it and flip between Original and MIDI. Too many short notes: raise the minimum note length. Notes missing: lower the sensitivity.
4. Set tempo to your Logic project tempo, then download the .mid.

Import into Logic

Drag the .mid from the Finder onto an existing software instrument track, or into the empty space below your tracks to get a new one. File → Import → MIDI File does the same thing.

Logic may ask whether to import the tempo information from the file. Choose No if your project tempo is already right — importing it replaces the tempo of the whole project. Choose Yes only in an empty project where you want Logic to take its tempo from the file.

The region lands at the playhead or wherever you dropped it. Move it so its start lines up with the bar you bounced from, and it should sit under the original audio note for note.

Common problems

• Notes drift away from the audio. The tempo in the converter did not match the project. Set it and export again rather than time-stretching the region.
• The whole project changed tempo. You answered Yes to importing tempo information. Undo, and import again with No.
• Notes an octave out. An overtone read as the note. Narrow the pitch range in the converter, or transpose those notes in the Piano Roll.
• Long, overlapping notes on guitar. Turn on trim overlaps before exporting.

Afterwards

Treat the region as a draft of the part. Logic’s Piano Roll quantize and velocity tools are the right place for the last round of fixes, and it is still faster than playing the part in again.