Cochlea

Compare two audio files (WAV, FLAC, mp3, or ogg) in feature space (loudness, onsets, pitch, key, timbre distance, per-segment RMS) rather than byte-for-byte, and report a verdict: byte-identical, tier-2 equivalent (within this workspace's cross-platform tolerances), or different (naming which dimensions diverge). Set spectrogram=true to also get a signed A→B difference heat map inline (red = louder in B, blue = quieter, black = unchanged) — 'what changed' as visible structure. Use this to check whether a re-render, edit, or platform change actually altered the audio in a way that matters — a `different` verdict is a normal, successful answer, not a tool failure.

The full beat grid of a whole WAV, FLAC, mp3, or ogg file, as JSON: every detected beat time (ms), the estimated downbeats, the tempo with its octave-alternative candidates, and a windowed stability score. This is the detail the compact `tempo` summary inside probe_audio drops — that one keeps only the count and mean interval to stay small. Use it to line events up to the beat, see where the downbeats fall, or weigh a half/double-tempo alternative. All times are measured from the start of the file.

Convert a cochlea RON score into a Standard MIDI File (format 1) — the inverse of import_midi. Timing exports exactly (score ticks become SMF ticks, the tempo map and time signature carry over); instruments become rough General MIDI program labels, since a synth preset isn't a GM instrument. Use this to hand a composed score to a DAW or notation tool, or to round-trip through external MIDI editing.

Convert a Standard MIDI File (format 0 or 1) into a cochlea RON score. Timing imports exactly (SMF ticks become score ticks, tempo events become the tempo map); General MIDI programs map to rough preset families and channel-10 percussion to kick/snare/hat tracks — every mapping guess comes back in the response so you can re-voice the score afterwards. Use this to bring existing musical material into the compose→render→probe loop.

Statically validate a RON score against the instrument/preset catalog — catches unknown instruments or inserts, empty tracks, and other semantic problems without rendering any audio. Use this before render_score to fail fast on authoring mistakes.

The loudness-over-time curve of a whole WAV, FLAC, mp3, or ogg file, as JSON: momentary (400 ms) and short-term (3 s) LUFS sampled every ~100 ms. This is the dynamics view the single integrated-LUFS / LRA summary in probe_audio can't give — where a mix gets loud, where a gate opens, how the level moves through a build or a chorus. Use it to check whether a change actually moved the dynamics, or to find the loudest moment. Every point's time is measured from the start of the file. (For a windowed analysis with an anchored offset, use probe_audio with from_s/to_s.)

Extract the full feature report (integrated LUFS/true peak/LRA, onsets, YIN pitch track plus quantized melody notes, MFCC timbre digest, chroma/key, a chord timeline and per-section key (harmony), tempo with octave-alternative candidates and stability, rhythm with grid alignment and a straight-vs-triplet grid call, stereo image, structural sections, silence, clipping — schema v5) from any WAV, FLAC, mp3, or ogg file, no score needed. Use this to 'listen' to audio through numbers: check loudness targets, confirm onset timing or tempo, read back the melody you composed, or see the chord progression. Pass from_s/to_s to zoom into a time window instead of probing the whole file (report times are then relative to the cut; source.start_ms anchors them).

The token-cheap way to listen to a WAV or FLAC file: a ~40-line deterministic text digest (duration, loudness, onsets, pitch, key, and a windowed timeline table) instead of a full JSON report or raw PCM. Reach for this first when you just need a sense of what's in a file, and only fall back to probe_audio when you need exact numbers to assert against.

Render a cochlea RON score (the declarative tick/track/note/automation IR) to a deterministic WAV mix. Use this to turn a composed score into audible PCM before probing or inspecting it. Set verify=true to also run the score's embedded `verify:` assertions and get the pass/fail report back in the same call.

The score-authoring reference: the complete RON score grammar (tracks, notes, durations, automation, easing), the live instrument-preset catalog with every automatable parameter and range, all embeddable verify: assertions, and a worked example. Call this FIRST when composing — everything render_score accepts is documented here; do not guess the format.

Render a mel spectrogram (or a tiled contact sheet covering the whole file) from a WAV, FLAC, mp3, or ogg file, for visual inspection of harmonic content, sweeps, or silence. The image comes back inline as MCP image content (base64 PNG) whenever it fits the size cap, so you can look at it directly without filesystem access; pass out_path to also (or instead) write the PNG to disk. Set annotate=true to draw what the analyzers heard onto the image — detected beats (orange ticks, top), onsets (cyan ticks, bottom), pitch segments (magenta lines) — and from_s/to_s to zoom into a time window. Use this when a numeric probe report isn't enough and you want to look at the audio.

Transcribe a WAV, FLAC, mp3, or ogg file into an editable cochlea RON score — the inverse of render_score, and the arrow that closes the compose loop: hear a sketch, get score back, revise it, render it again. Pitch-tracks the melody, reads its timing against a tempo (detected from the audio unless you pass bpm), quantizes to a note grid, and estimates each note's velocity from its peak level. Deliberately monophonic: it hears one line, so chords, drums, and dense mixes come back as whichever line the tracker locked onto. Every assumption — the tempo, the grid, the preset, clamped or dropped notes — comes back in the response, so treat the result as a draft to re-voice rather than a faithful score.