Open Format · Version 1.0

Procedural
Music Format

An open format for the recipe behind procedurally generated music.
Not the audio. Not the score. The instructions.

PMF 1.0 MIT License
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What PMF stores

Everything the engine knows.
Nothing the audio file does.

A .pmf file is the complete description of a composition — readable by humans, LLMs, and any JSON tool.

01

Summary

Engine-generated natural language. An LLM reads this first and understands the composition without parsing anything else.

02

Identity

Seed, key, BPM with tempo label, mood, bar count. The fingerprint of the composition.

03

Harmony

Chord progression as names and scale degrees, bass pattern, arp structure — musical vocabulary, not MIDI numbers.

04

Melody

Motifs in ABC notation with interval and rhythm descriptions. The only note format with proven LLM research behind it.

05

Arrangement

Section names (Intro, Groove, Lift), bar-gain masks per stem, melody-on bars. The dynamic shape of the loop.

06

Synthesis · FX · Mix

Voice parameters, reverb room, delay type, sidechain depth. Engine-defined but structured with semantic labels.

synthwave-example.pmf
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{
  "pmf_version": "1.0",
  "engine":      "synthwave_engine",
  "summary":     "Mid-tempo NightDrive in A minor
               at 128 BPM. Sparse intro
               builds to full mix by bar 4.",
  "identity": {
    "seed":      42,
    "mood":      "NightDrive",
    "bpm":       128.0,
    "bpm_label": "mid-tempo synthwave",
    "key":       "A minor",
    "bars":      8
  },
  "harmony": {
    "progression":  ["Am","F","C","G"],
    "progression_degrees": ["i","VI","III","VII"],
    "progression_label":  "minor turnaround"
  },
  "melody": {
    "motif_a": {
      "abc":   "A2 c B A4",
      "label": "ascending minor third"
    }
  }
}
Format

Designed to be read by AI as much as by humans.

Musical vocabulary throughout — chord names, scale degrees, tempo labels, reverb room names. Not raw indices and floats. An LLM that knows music theory reads a PMF file without documentation.

ABC notation handles melody motifs — the only text-based note format with serious LLM research behind it (ChatMusician 2024, ABC-Eval 2025).

Context

Why not MIDI, MusicXML, or ABC?

Every existing format was built for a different job. PMF fills the gap they all leave open.

format
MIDI
Performance capture. Stores note-on, note-off, velocity, and timing events.
Binary format No compositional intent No seed or mood
format
MusicXML
Score printing and notation software interchange.
XML verbosity Poor LLM efficiency No generative params
format
ABC Notation
Score transcription. Best text format for note sequences.
Note-level only No arrangement structure No seed or engine params
format
PMF
The compositional recipe. Describes how to generate music, not music that already exists.
Seed + mood + arrangement Musical vocabulary ABC for melody motifs
Resources

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