Free online AAC to MSCZ converter

An AAC file stores compressed audio, while an MSCZ file stores an editable musical score for MuseScore. Converting one into the other requires transcribing the recorded performance into notes; it is not a direct audio-format conversion.

What the AAC format is

AAC (Advanced Audio Coding) is a lossy audio codec used for music, podcasts, voice recordings, and streaming. Apple Music, iTunes, phones, screen recorders, and many media applications commonly create or export .aac files, although AAC audio is also frequently stored inside .m4a or .mp4 containers.

The file contains sampled sound, not note names, measures, clefs, dynamics, or other notation data. Encoding settings such as bitrate and compression can also obscure transients and harmonics needed for accurate transcription.

What the MSCZ format is

MSCZ is MuseScore's compressed native score format. It stores notation objects such as pitches, durations, rests, voices, instruments, tempo markings, lyrics, articulations, layout, and playback data.

MuseScore can edit and play MSCZ scores and export them to formats such as PDF, MusicXML, MIDI, and audio. MSCZ is suitable when the result must remain editable in MuseScore; it is not suitable for storing the original recording.

How to actually convert AAC to MSCZ

Use audio transcription, followed by score creation or MIDI import:

1. Open the AAC file in an audio player or editor. If an application does not accept AAC directly, decode it to WAV with FFmpeg: ffmpeg -i recording.aac recording.wav.
2. For a simple monophonic melody, identify the key, meter, tempo, pitches, and note lengths by listening. Enter them in MuseScore with the note-entry tools, then choose File → Save As and save as score.mscz.
3. For an automated starting point, process the WAV with a pitch-to-MIDI application such as Spotify Basic Pitch. Open the resulting .mid file in MuseScore using File → Open, select the correct instruments and quantization settings in the MIDI import dialog, correct the notation, and save it as .mscz.
4. For polyphonic recordings, separate stems first when possible, transcribe each instrument, and check chords, rhythms, tuplets, tied notes, pedal tones, and tempo changes manually.

The built-in converter on 101convert.com can be used free without installing software for supported file conversions, but no ordinary file converter can reliably infer a complete editable score from AAC audio alone. A result advertised as AAC-to-MSCZ must use audio-to-MIDI or music-transcription analysis rather than simple format conversion.

Quality and compatibility limitations

Automatic transcription is most reliable for a clean, single-instrument melody with steady tempo. Drum parts, dense chords, reverberation, background instruments, expressive timing, and lossy AAC compression substantially increase recognition errors.

MIDI contains performance events rather than finished notation, so MuseScore may import excessively short notes, incorrect rests, awkward beaming, missing ties, or several voices on one staff. Correct the imported score before sharing or exporting it. FFmpeg can decode AAC audio, but it cannot create musical notation or an MSCZ score.