Freedom251 › AI Music Generators
BELLOWS
What BELLOWS is
BELLOWS is a free, open-source audio engine that also works as an interactive browser instrument and workbench. Its browser tools include synthesizers, drum machines, samplers, SoundFont playback, sequencing, and effects, with 18 built-in synthesizers. You can play through a mouse, computer keyboard, or MIDI controller, then load SoundFont files or your own samples across a keyboard. A seed word generates beats, basslines, melodies, and chords, and repeating the seed recreates the same song. The workbench records music to WAV without an account or upload. Developers can install the library with npm, load it from unpkg or jsDelivr, or use it in Vite and webpack applications. It also runs in Node to render WAV files without a browser. BELLOWS supports more than 30 scales, chord parsing, voice leading, negative harmony, EDO and just-intonation tunings, WAV and MIDI handling, Web MIDI where available, and WebCodecs Opus export where available.
Who it suits
BELLOWS suits musicians experimenting in a browser and developers embedding audio tools in web or Node projects. It is also useful for anyone who needs repeatable generative parts, imported samples, or WAV rendering.
What it does well
- Free and open source
- 18 built-in synthesizers
- Seed-based repeatable music generation
- Browser recording to WAV
- Node rendering without a browser
What to know first
- Requires AudioWorklet support
- Web MIDI limited to some browsers
- No native desktop platform listed
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| BELLOWS | Free, open source audio engine | Free |
As bellows.live lists them, read 12 Oct 2026. The maker's own page has the final word.
Verdict
BELLOWS combines browser performance, generative composition, recording, and a developer-focused audio library in one free package. Its browser requirements and Web MIDI limits matter when choosing a setup.
Facts from BELLOWS's own pages
- Audio engine
- The library uses an AudioWorklet kernel that schedules events on the audio thread for sample-accurate timing. · github.com, 12 Oct 2026
- Browser requirements
- AudioWorklet is required; the repository lists Chrome 66+, Firefox 76+, and Safari 14.1+ as supported, while Web MIDI is limited to Chromium and Firefox. · github.com, 12 Oct 2026
- Built-in instruments
- The site says BELLOWS includes 18 built-in synthesizers and supports playing with a mouse, keyboard, or MIDI controller. · bellows.live, 12 Oct 2026
- Commercial use
- Yes · bellows.live, 22 Sept 2026
- Formats and MIDI
- The library supports WAV encoding and decoding, standard MIDI file read and write, Web MIDI where available, and WebCodecs Opus export where available. · github.com, 12 Oct 2026
- Free plan
- Yes · bellows.live, 22 Sept 2026
- Generative music
- A seed word can generate beats, basslines, melodies, and chords, with the same seed producing the same song each time. · bellows.live, 12 Oct 2026
- Import sounds
- Users can load SoundFont files or their own audio samples and play them across a keyboard. · bellows.live, 12 Oct 2026
- License
- The project is released under the Apache-2.0 license. · bellows.live, 12 Oct 2026
- Maker
- The site identifies Moheeb Zara (@virgilvox), hack.build, as the maker. · bellows.live, 12 Oct 2026
- Music theory
- The library supports more than 30 scales, chord parsing, voice leading, negative harmony, and tunings including EDO and just intonation. · github.com, 12 Oct 2026
- Offline rendering
- The engine can run in Node without a browser to render songs to WAV files. · bellows.live, 12 Oct 2026
- Supported platforms
- web · bellows.live, 22 Sept 2026
- Product
- BELLOWS is a free, open source audio engine and interactive browser instrument and workbench. · bellows.live, 12 Oct 2026
- Recording
- The browser workbench can record music to a WAV file, and the site says it requires no account or upload. · bellows.live, 12 Oct 2026
- Sound tools
- The engine includes synthesizers, drum machines, samplers, soundfont support, sequencing, and effects. · bellows.live, 12 Oct 2026
- Use in projects
- The library can be installed with npm, loaded from unpkg or jsDelivr, or imported into apps built with Vite or webpack. · bellows.live, 12 Oct 2026
Where BELLOWS stands on Freedom251
- AI Music Generators#107 of 123