Baba O`Riley... Sorry.

Experimental synthesizer/sequencer in Go that plays events (notes) from JSON and saves the output to a WAV file. The name is inspired by the song Baba O'Riley by The Who.

Disclaimer

While developing this application, I in no way intended to offend the artistic legacy of The Who. If the quality of the performance of Baba O’Riley seemed inappropriate — I am truly sorry that it turned out this way...

Features

• Playback of events (notes) from JSON.
• Support for different instruments (Kick, Snare, BassSynth, PolySynth, ArpSynth).
• Rendering to mono WAV (16-bit PCM).
• Multithreaded generation: each instrument is processed in its own goroutine.

Project Structure

baba-oriley/
├── assets/           # JSON files with notes
├── out/              # Output folder for generated .wav files
├── internal/
│   ├── audio/        # WAVWriter and audio handling
│   ├── instruments/  # Instruments (Kick, etc.)
│   └── player/       # Logic for loading and playing events
└── cmd/
    └── main.go       # Entry point

Example JSON (assets/demo.json)

[
  {"start": 17.70, "duration": 0.59, "note": 72, "velocity": 105, "instrument": "arp3"},
  {"start": 9.60, "duration": 0.28, "note": 72, "velocity": 105, "instrument": "arp1"}
]

Running

Build and run:

go run ./cmd

After that, a baba.wav file will appear in the out/ folder.

Adding Instruments

A new instrument must implement the method:

Play(note int, velocity int, duration float64, sampleRate int) []int16

and be registered in instruments. Example: the Kick (bass drum) is synthesized as a decaying sine wave.

TODO

• Implement stereo support.
• MIDI import/export.
• Real-time player.