utterance

Derive music from the structure of a voice.

A recording of someone speaking for half a minute is not treated as a sound to play back, pitch-shift or resynthesise. It is treated as a source of law. The aim: the speaker's prosody, stress hierarchy, vowel geometry and measured harmonic series become the constraints, and the music is what falls out when those constraints are run.

The output is not meant to sound like a voice. Two people reading the same sentence should produce audibly different pieces, each internally consistent.

The chain runs end to end: guided calibration takes yield a scale and a timbre derived from the speaker's own spectrum; an utterance in that world yields a score; the score renders to audio. The browser records takes, shows each voiceprint, plays the derived music with every mapping choice on a slider, and compares two settings side by side. docs/roadmap.md says what is next and which decisions are settled.

Layout

Path	What it is
utterance-analysis	Pure DSP core: audio in, voiceprint out. No IO, no opinions.
utterance-mapping	Musical decisions over a voiceprint. Where the opinions live.
utterance-realisation	Score to audio. Additive synthesis, no decisions.
src	axum server: recordings, analysis, renders, the static bundle.
src/bin	Research tools that measure what the mappings do.
frontend	Angular app: capture, calibrate, inspect, listen, compare.
android	A WebView wrapper with microphone access.
docs	Design intent. Start with architecture.md, then roadmap.md.

Running locally

While working on the code — live reload, backend and frontend separate:

scripts/dev.sh            # backend on :8181, ng serve on :4200 with /api proxied

Then open http://localhost:4200.

To just use it, serving the built bundle and the API from one origin:

nix develop -c bash -c 'cd frontend && pnpm install --frozen-lockfile && pnpm run build'
BIND_ADDR=0.0.0.0:8181 \
  DATA_DIR="$PWD/data" \
  STATIC_DIR="$PWD/frontend/dist/utterance-web/browser" \
  nix develop -c cargo run --release

Then http://localhost:8181. Binding 0.0.0.0 also serves the LAN, so another device can browse takes and inspect voiceprints — but not record: browsers only grant microphone access in a secure context, which localhost is and a plain-HTTP LAN address is not.

Backend alone, API only:

nix develop -c cargo run

Recordings live in data/, one directory per take holding the audio, its voiceprint and a little metadata. Deleting data/ is a supported way to start over; the audio is the only thing not recoverable, since voiceprints are re-derived automatically whenever the analyser moves on.

Verifying

nix run ../dev-lint#gate -- . gate.json   # every check in gate.dhall
scripts/setup-hooks.sh                    # one-time per clone: pre-commit runs the gate