To turn one part of a finished song into MIDI, isolate the clearest version of the melody, bass, vocal line, or chord phrase, set its tempo, then convert and correct the draft. Do not ask the converter to untangle the whole mix. MIDI stores note events, not the original tone, effects, or mix, so compare every important note with the audio.
Choose one musical job
Name what the MIDI must do. A focused part is easier to judge than a vague request to convert the song, and its completion test should describe a musical use, not merely the existence of a .mid file.
- Bass line: capture the main pitches and rhythm so you can change its sound or harmony.
- Lead melody: make the contour editable for arranging, notation, or another instrument.
- Vocal line: make a note guide without claiming to preserve words, expression, or timbre.
- Exposed chord phrase: capture a small voicing, then inspect every note closely.
- Drums or a full arrangement: use a dedicated transcription workflow; this guide does not promise either result.
Start with audio you may process
Use a recording you created or have permission to process. Separation and transcription do not clear a sample, remix, or release. Keep the original unchanged and label working files so a draft cannot be mistaken for an authorized score or session export.
Decide whether the source already isolates the part
If you have a solo recording, official stem, or clean bounce from your own session, take it straight to Audio to MIDI. Otherwise find a section where the target is exposed. A sparse verse bass line or unaccompanied vocal can be more useful than a whole track with constant overlap.
For a finished mix, a 4-Stem Split can produce vocals, drums, bass, and an others file. A vocal or bass stem may clarify the target. Others can contain several instruments, effects, and bleed; it is not a solo guitar, piano, or synth track. If the target remains buried, choose a sparser passage or replay or hum the line instead of converting the same mixed stem repeatedly.
Use Stem Splitter only when it improves the source
- Open Stem Splitter and upload an authorized track, or choose an eligible My Music song.
- Select 4-Stem Split and start the signed-in separation.
- Preview the target alone, then compare it with the original mix.
- Download the vocal or bass only if the intended line is clearer.
- Keep the original; separation estimates working parts, not recording-session tracks.
Judge the audio, not the label. Listen for note starts, endings, and rests. Kick bleed can add short false bass notes; harmony bleed can add pitches behind a vocal; reverb can blur note endings. Mark those risks before conversion.
Prepare the shortest useful phrase
Make a working clip of only the phrase you need. Keep enough lead-in for the first attack and enough tail for the final note, then record its original bar or timestamp. Avoid repeated format conversions and aggressive processing; neither separates the musical part.
- Prefer a clean source over a speaker recording or repeatedly compressed file.
- Choose a passage where the target is distinct from competing sounds.
- Leave intentional rests intact; they help define note boundaries.
- Include enough context to distinguish a real octave move from an error.
- Write down the tempo and original location before opening the converter.
Set tempo for a useful MIDI grid
Enter the source tempo as closely as you can. Audio to MIDI accepts 40-220 BPM and writes the result against that tempo. It gives the MIDI a useful grid; it does not quantize loose playing or repair tempo changes. For a drifting live recording, use a stable short passage or realign the notes later.
Convert the clearer audio locally
- Open Audio to MIDI and choose Upload. It shows WAV, MP3, FLAC, and OGG sources.
- Load the prepared phrase or stem and enter its tempo.
- Choose Convert to MIDI. The conversion runs in your browser rather than uploading the source for transcription.
- Note the reported note count and duration. A crowded result is a reason to inspect the source, not proof of extra detail.
- Download the MIDI or choose Open in MIDI Editor. Sign in only if you want to save the conversion to My Music.
Check the note shape before choosing a sound
Open the draft with a simple sound suited to its register, then compare it with the source. Ignore the different timbre and check the musical shape: starting pitch, contour, main rhythm, long notes, rests, and final note. A recognizable but rough line can be workable material.
- Delete short notes that follow kick, breath, pick, or cymbal bleed rather than the target part.
- Correct isolated octave jumps after checking the audio; do not flatten a real register change.
- Add or move the main notes that are clearly missing or late before polishing smaller ornaments.
- Shorten notes that run through audible rests, and lengthen only where the source sustains.
- Adjust velocity after pitch and timing. Velocity cannot repair a wrong note or a crowded source.
Work through a fictional bass-line example
Imagine an authorized song with a clear eight-bar verse bass phrase and dense chorus drums. The bass stem clarifies the verse but still carries chorus kick attacks, so transcribe only the verse. Mark its original bar, prepare the short clip, enter the tempo, and convert locally.
In the MIDI Editor, compare each downbeat with the stem and original. Remove a short note caused by kick bleed; correct an octave jump only after listening again. Keep a slide or grace note only if it helps the new part. The draft should follow the core pitches and rhythm, not reproduce the player's tone or every transition.
Diagnose a crowded or inaccurate result
- Too many notes: use a clearer stem or shorter exposed passage with less percussion, accompaniment, or reverb.
- Wrong octaves: correct isolated errors after listening, or replay the phrase cleanly.
- Notes miss the bars: recheck BPM and tempo stability; the converter does not quantize.
- Missing main notes: try a stronger passage instead of boosting everything or converting repeatedly.
- Crowded chords: keep only the voices required by the arrangement and verify each pitch.
- No useful notes: return to a solo recording, official stem, replay, or hum.
Know when replaying is the efficient choice
A stem can be a useful reference even when it is not clean enough to convert. If the target stays mixed, map it by ear, replay it with a MIDI instrument, or record a clean hum. This avoids spending longer deleting false notes than rebuilding a simple phrase.
Common mistakes
- Expecting a mastered mix to produce a separate MIDI track for every instrument.
- Treating others as isolated piano, guitar, or synth without listening first.
- Correcting shifted notes before checking the BPM.
- Using damaged audio when a cleaner source or sparse passage exists.
- Trying to recover the original tone or effects from MIDI note events.
- Distributing the transcription without confirming the required permissions.
Completion check
- You may process the source for this work.
- One target part and one downstream job are defined.
- The chosen phrase or stem is clear and its original location is recorded.
- The MIDI uses a helpful tempo and follows the main pitch, rhythm, and rests.
- False notes, octave errors, missing notes, and lengths are checked against the audio.
- The original audio, working stem, rough MIDI, and edited MIDI are labeled separately.
- The result remains an editable draft, not an official score, session track, or rights clearance.
Open Audio to MIDI when you have one clear musical part and a tempo. Convert the shortest useful source, send the draft to the MIDI Editor, and stop only when the notes do the job you named at the start.