Pulsar is a small, readable music language and a studio-grade synthesis engine. An AI model writes a song, renders it, reads a mix report instead of listening — and iterates until it sounds right.
We handed a new agent nothing but the language reference and the CLI. It composed this deep house track, rendered it six times, and used the mix report to fix its balance and energy arc. Every sound is synthesized, including the vocal: an original lyric sung by a neural voice — no samples, no recorded singers.
Rhythms use TidalCycles-style mini-notation, wrapped in a tiny conventional syntax: tracks, sections that extend each other, play, automate, arrange — plus variables, functions, lambdas, loops and conditionals.
Am9, Fmaj7) and roman numerals in the song's key, with smooth voice-leading.tempo 122 key "A minor" track kick = drums("house") track bass = synth("moog_bass", duck: 0.6) >> comp(ratio: 3) track pad = synth("pad", reverb: 0.4, duck: 0.6) let prog = "<Am9 Dm9 Fmaj9 Em7>" section intro 8 { play kick "bd*4, [~ hh]*4" play pad prog.voicing("smooth") automate pad.cutoff 0.25 -> 0.5 } section drop 16 extends intro { play kick "bd*4, ~ cp ~ cp, [~ hh]*4" play bass "<a1 d2 f1 e1>".struct("x ~ ~ x ~ ~ x ~") } arrange intro, drop, drop
Pulsar renders every note individually at 96 kHz through Faust DSP compiled to native code, places it sample-exactly, and masters the result to a loudness target.
Band-limited oscillators with unison and drift through Moog ladder, TB-303 diode, Korg MS-20 and Oberheim SEM filter models. Plus FM and Karplus-Strong engines.
Every preset is loudness-calibrated with a balanced fader, so a song that only picks presets already sits right in the mix.
Zita reverb, ping-pong delay, sidechain ducking, glue compression, a 4× oversampled soft clipper and a true-peak limiter.
54 Kokoro text-to-speech voices that sing your lyrics on your melody — one word per note, re-pitched with formants preserved, doubled for width. Or speak lines on the beat.
Pitch, slice, gate and fit any audio file to the grid — one-shots, loops and chops.
A model can't listen, so every render tells it what an engineer would hear: loudness, true peak, tonal balance per band, stereo image, the energy arc of each section, per-track levels, frequency masking between tracks — and concrete fixes.
Match a reference you own with pulsar compare and pulsar match, or fit a synth patch to a recording's timbre with pulsar timbre.
loudness -10.0 LUFS true peak -1.0 dBTP crest 10.2 dB spectrum: sub +0 bass -1 low_mid -3 mid -11 presence -17 stereo: correlation 0.93, width 0.19 energy arc: intro bar 0 -12.1 LUFS drop bar 24 -8.8 LUFS breakdown bar 40 -14.0 LUFS drop2 bar 64 -8.5 LUFS tracks: kick peak -3.9 dB rms -20.8 dB mostly sub keys peak -5.2 dB rms -25.6 dB mostly low_mid - chord and keys both peak in the low_mid band and may mask each other; separate them by octave, eq, or pan
A native editor with an Ableton-style arrangement beside it. Piano rolls for melodic tracks, one row per voice for drums, automation curves under their tracks, sections on the ruler — and a playhead that lights up notes as they sound. It recompiles as you type.
Every edit re-renders the view in a fraction of a second; errors are marked inline.
Pinch to zoom time, ⌥-pinch to stretch lanes taller, click the ruler to move the playhead.
⌘R renders in parallel across your cores and plays; renders are cached per source.
An MCP server exposes referencecheckrenderanalyze_fileplay so Claude or any MCP client can compose, render, read the report and revise in a loop.
# give Claude Code a music studio claude mcp add pulsar -- /path/to/pulsar/.venv/bin/pulsar mcp # or drive it yourself pulsar docs # the reference, ready for a prompt pulsar check song.pulse pulsar render song.pulse -o song.mp3 pulsar render song.pulse --only drop # fast iteration
Python 3.10+ on macOS or Linux. ffmpeg for MP3 export. The Studio app needs only the Xcode command line tools.
git clone https://github.com/ronreiter/pulsar && cd pulsar uv venv --python 3.12 .venv && uv pip install --python .venv/bin/python -e ".[mcp,dev]" .venv/bin/pulsar render examples/deep_house_agent.pulse --play app/build_app.sh && open "app/build/Pulsar Studio.app"