"""muse compare — semantic comparison between two MIDI snapshots. Diffs two commits (or a commit and the working tree) on multiple musical dimensions: note count, harmonic content, rhythmic feel, pitch range, and density. Where ``muse diff`` shows note-level insertions/deletions, this command shows the *musical meaning* of what changed. Usage:: muse compare tracks/melody.mid HEAD~1 HEAD muse compare tracks/piano.mid HEAD~3 HEAD~1 muse compare tracks/bass.mid HEAD --working-tree muse compare tracks/chords.mid HEAD~1 HEAD --json Output:: Semantic comparison: tracks/melody.mid A: HEAD~1 (cb4afaed) B: HEAD (9f3a12e7) Dimension A B Δ ────────────────────────────────────────────────────────── Notes 48 56 +8 Bars 16 16 0 Key G major G major = Density avg 3.0/beat 3.5/beat +0.5 Swing ratio 1.00 1.38 +0.38 (swing added) Syncopation 0.12 0.31 +0.19 (more syncopated) Quantisation 0.98 0.84 -0.14 (more human) """ from __future__ import annotations import argparse import json import logging import pathlib import sys from muse.core.errors import ExitCode from muse.core.repo import read_repo_id, require_repo from muse.core.store import read_current_branch, resolve_commit_ref from muse.plugins.midi._analysis import analyze_rhythm, analyze_density from muse.plugins.midi._query import ( NoteInfo, key_signature_guess, load_track, load_track_from_workdir, ) logger = logging.getLogger(__name__) def _read_branch(root: pathlib.Path) -> str: return read_current_branch(root) def _load( root: pathlib.Path, track: str, ref: str, repo_id: str, branch: str, ) -> tuple[list[NoteInfo], int, str]: commit = resolve_commit_ref(root, repo_id, branch, ref) if commit is None: print(f"❌ Commit '{ref}' not found.", file=sys.stderr) raise SystemExit(ExitCode.USER_ERROR) result = load_track(root, commit.commit_id, track) if result is None: print(f"❌ Track '{track}' not found in commit '{ref}'.", file=sys.stderr) raise SystemExit(ExitCode.USER_ERROR) return result[0], result[1], commit.commit_id[:8] def register(subparsers: "argparse._SubParsersAction[argparse.ArgumentParser]") -> None: """Register the compare subcommand.""" parser = subparsers.add_parser("compare", help="Compare two MIDI snapshots across musical dimensions.", description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter) parser.add_argument("track", metavar="TRACK", help="Workspace-relative path to a .mid file.") parser.add_argument("ref_a", metavar="REF_A", help="First commit reference (older).") parser.add_argument("ref_b", nargs="?", metavar="REF_B", default=None, help="Second commit reference. Omit to compare REF_A against the working tree.") parser.add_argument("--json", action="store_true", dest="as_json", help="Emit results as JSON.") parser.set_defaults(func=run) def run(args: argparse.Namespace) -> None: """Compare two MIDI snapshots across musical dimensions. ``muse compare`` goes beyond raw note diffs — it shows how key, density, swing, syncopation, and quantisation changed between two points in history. For agents: use this after a merge to verify that the merged result preserves the intended musical character of both parent branches. """ track: str = args.track ref_a: str = args.ref_a ref_b: str | None = args.ref_b as_json: bool = args.as_json root = require_repo() repo_id = read_repo_id(root) branch = _read_branch(root) notes_a, _tpb_a, label_a = _load(root, track, ref_a, repo_id, branch) if ref_b is not None: notes_b, _tpb_b, label_b = _load(root, track, ref_b, repo_id, branch) else: raw_b = load_track_from_workdir(root, track) if raw_b is None: print(f"❌ Track '{track}' not found in working tree.", file=sys.stderr) raise SystemExit(ExitCode.USER_ERROR) notes_b, _tpb_b = raw_b label_b = "working tree" rh_a = analyze_rhythm(notes_a) rh_b = analyze_rhythm(notes_b) dens_a = analyze_density(notes_a) dens_b = analyze_density(notes_b) avg_dens_a = sum(d["notes_per_beat"] for d in dens_a) / max(len(dens_a), 1) avg_dens_b = sum(d["notes_per_beat"] for d in dens_b) / max(len(dens_b), 1) key_a = key_signature_guess(notes_a) key_b = key_signature_guess(notes_b) if as_json: print(json.dumps({ "track": track, "a": {"ref": ref_a, "sha": label_a, "rhythm": rh_a, "key": key_a, "density_avg": round(avg_dens_a, 2)}, "b": {"ref": ref_b or "working tree", "sha": label_b, "rhythm": rh_b, "key": key_b, "density_avg": round(avg_dens_b, 2)}, }, indent=2)) return print(f"\nSemantic comparison: {track}") print(f"A: {ref_a} ({label_a}) B: {ref_b or 'working tree'} ({label_b})\n") print(f" {'Dimension':<22} {'A':>16} {'B':>16} {'Δ':<30}") print(" " + "─" * 90) def row(dim: str, va: str, vb: str, delta: str) -> None: print(f" {dim:<22} {va:>16} {vb:>16} {delta:<30}") row("Notes", str(rh_a["total_notes"]), str(rh_b["total_notes"]), f"{rh_b['total_notes'] - rh_a['total_notes']:+d}") row("Bars", str(rh_a["bars"]), str(rh_b["bars"]), f"{rh_b['bars'] - rh_a['bars']:+d}") row("Key", key_a, key_b, "=" if key_a == key_b else f"{key_a} → {key_b}") row("Density avg", f"{avg_dens_a:.2f}/beat", f"{avg_dens_b:.2f}/beat", f"{avg_dens_b - avg_dens_a:+.2f}") row("Swing ratio", f"{rh_a['swing_ratio']:.3f}", f"{rh_b['swing_ratio']:.3f}", f"{rh_b['swing_ratio'] - rh_a['swing_ratio']:+.3f}") row("Syncopation", f"{rh_a['syncopation_score']:.3f}", f"{rh_b['syncopation_score']:.3f}", f"{rh_b['syncopation_score'] - rh_a['syncopation_score']:+.3f}") row("Quantisation", f"{rh_a['quantization_score']:.3f}", f"{rh_b['quantization_score']:.3f}", f"{rh_b['quantization_score'] - rh_a['quantization_score']:+.3f}") row("Subdivision", rh_a["dominant_subdivision"], rh_b["dominant_subdivision"], "=" if rh_a["dominant_subdivision"] == rh_b["dominant_subdivision"] else "changed")