Initial release: procedural techno music generator

Synthesizes kick, snare, hi-hat, bass, and acid lead from scratch.
32-bar song structure with filter sweeps and pattern variation.
Outputs raw float32 stereo at 44.1 kHz to stdout.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

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+# techno-gen
+
+Generates infinite procedural techno music as raw float32 stereo audio on stdout.
+138 BPM. No samples — everything is synthesized from scratch.
+
+## Build
+
+```sh
+make
+```
+
+Or manually:
+
+```sh
+gcc -O2 -Wall -lm -o techno-gen techno-gen.c
+```
+
+## Play
+
+Pipe directly into `paplay` (PulseAudio):
+
+```sh
+./techno-gen | paplay --format=float32le --rate=44100 --channels=2
+```
+
+> **Note:** `paplay` is part of the `pulseaudio-utils` package.
+> On Debian/Ubuntu: `sudo apt install pulseaudio-utils`
+
+### Mono version (if you only want 1 channel)
+
+The program outputs stereo (2 channels). If you want mono, mix down with sox:
+
+```sh
+./techno-gen | sox -t raw -r 44100 -e float -b 32 -c 2 - -t raw -r 44100 -e float -b 32 -c 1 - | paplay --format=float32le --rate=44100 --channels=1
+```
+
+### Record to file
+
+```sh
+./techno-gen | sox -t raw -r 44100 -e float -b 32 -c 2 - output.wav trim 0 120
+```
+
+This records 2 minutes (`trim 0 120`) to `output.wav`.
+
+## What it sounds like
+
+| Time          | Section                                            |
+|---------------|----------------------------------------------------|
+| 0–3 bars      | **Intro** — kick + bass, filter closed             |
+| 4–7 bars      | **Rise** — hi-hats join, filter opens              |
+| 8–15 bars     | **Full** — snare, acid lead, LFO filter sweeps     |
+| 16–19 bars    | **Breakdown** — bass only, stripped down           |
+| 20–23 bars    | **Build** — kick returns, filter climbs            |
+| 24–31 bars    | **Heavy** — syncopated kick, acid variation 2      |
+| *then loops*  | Back to bar 8 (never the sparse intro again)       |
+
+The cycle is 32 bars (~1 min 23 sec at 138 BPM), then repeats with continuous filter and pattern variation.
+
+## Synthesis
+
+All audio is synthesized in real time:
+
+- **Kick** — sine oscillator with pitch envelope (200 → 45 Hz), amp decay, transient click
+- **Snare** — high-pass filtered noise blended with a 185 Hz tone
+- **Hi-hat** — noise through a 7 kHz high-pass; open/closed variants with different decay times
+- **Bass** — sawtooth oscillator through a resonant (Q=4.5) biquad low-pass with per-note filter envelope and glide
+- **Acid lead** — dual slightly-detuned sawtooth through a very resonant (Q=6) low-pass; filter sweeps with LFO per section
+- **Stereo width** — short delay line (~11 ms) ping-ponged between channels on hats and acid
+- **Master** — `tanh` soft saturation to keep levels honest