Small, clean and widely supported
AAC is more efficient than MP3, so it keeps rendered MIDI music clean at moderate bitrates. It plays on iPhones, Android phones, smart TVs, car systems and in browsers. Convert MIDI to AAC when you want compact audio for a device or an app that lists AAC among its formats.
Plain AAC stream versus M4A
This page saves a raw .aac stream, which is what some devices, players and apps ask for. A raw stream has no container, so it cannot hold a song title or artwork. For a music library, iPhone or the Apple Music app, MIDI to M4A is more convenient: same AAC sound, with tags. For an iPhone ringtone, choose MIDI to M4R.
Bitrate guide
| Music | AAC bitrate | Size per minute |
|---|---|---|
| Solo piano or simple melody | 128 kbps | about 1 MB |
| Band or full arrangement | 160–192 kbps | 1.2–1.4 MB |
| Orchestral or very dense | 256 kbps | about 1.9 MB |
Synthesized sound has sharp attacks and clear high frequencies. If you hear a slightly "swirly" sound on cymbals or strings at low bitrates, go one step higher.
Where the sound comes from
A MIDI file has no sound of its own. Its notes, tempo and instrument numbers are played here by a General MIDI soundfont synthesizer, and that synthesizer output is what gets encoded. Listen to the preview first: if the result is fine there, the AAC will sound the same.
Typical uses
- Background music for an app or a kiosk that plays AAC files.
- Practice tracks for a portable player or a car system with USB input.
- Small files to send over a messenger without the recipient needing a MIDI player.
If a track ends too abruptly or starts with silence, trim it in the audio editor. Raw AAC files have no index, so a few players show the length only roughly; this does not affect playback.