claude-music-cover

claude-music-cover — Cover/Style Transfer

Worked example (input → command → output)

User: "Turn this pop song into a jazz cover" (hands over ~/Music/my_song.flac)

Command:

bash ~/.claude/skills/claude-music/scripts/music_engine.sh \
  --quality standard \
  cover \
  --src-audio "$HOME/Music/my_song.flac" \
  --caption "smooth jazz, saxophone, piano trio, warm, live recording feel" \
  --cover-strength 0.5

Expected JSON on stdout:

{
  "success": true,
  "task_type": "cover",
  "model": "acestep-v15-turbo",
  "outputs": [
    {"path": "/home/$USER/Music/claude-music-output/cover_20260416_121040_01.flac",
     "seed": 4921, "size_mb": 2.47, "index": 1},
    {"path": "/home/$USER/Music/claude-music-output/cover_20260416_121040_02.flac",
     "seed": 81244, "size_mb": 2.52, "index": 2}
  ],
  "params": {
    "src_audio": "/home/$USER/Music/my_song.flac",
    "cover_strength": 0.5,
    "caption": "smooth jazz, saxophone, piano trio, warm, live recording feel"
  },
  "timing": {"generation_sec": 29.4},
  "count": 2
}

Note: --cover-strength maps to ACE-Step's cover_noise_strength (0.0 = fully reimagine source, 1.0 = stay close to source). The code passes src_audio + cover_noise_strength — the older reference_audio/audio_cover_strength field names are wrong and guarded by a regression test.

Pre-Flight

Verify source audio exists: bash ~/.claude/skills/claude-music/scripts/preflight.sh "$SRC_AUDIO" "$OUTPUT"
Check GPU: bash ~/.claude/skills/claude-music/scripts/detect_gpu.sh

Usage

# Jazz cover of a pop song
bash ~/.claude/skills/claude-music/scripts/music_engine.sh cover \
  --src-audio /path/to/original.mp3 \
  --caption "smooth jazz, saxophone, piano trio" \
  --cover-strength 0.5

# Same genre, different mood
bash ~/.claude/skills/claude-music/scripts/music_engine.sh cover \
  --src-audio song.flac \
  --caption "acoustic version, stripped back, intimate" \
  --cover-strength 0.7

# Complete reimagination
bash ~/.claude/skills/claude-music/scripts/music_engine.sh cover \
  --src-audio track.wav \
  --caption "electronic, synthwave, 80s retro" \
  --cover-strength 0.2

# Cover with new lyrics
bash ~/.claude/skills/claude-music/scripts/music_engine.sh cover \
  --src-audio original.mp3 \
  --caption "rock, electric guitar, powerful male vocal" \
  --lyrics "[Verse] New lyrics here..." \
  --cover-strength 0.5

Cover Strength Guide

--cover-strength controls cover_noise_strength (how much of the source audio's latent is preserved):

Value	Effect	Use When
0.0	Pure noise — complete reimagination, only caption guides output	Major genre transformation
0.2-0.3	Loose inspiration — new arrangement, some structural similarity	Different genre/mood
0.4-0.5	Moderate transfer — recognizable structure, new details	Balanced cover (default)
0.6-0.7	Faithful adaptation — preserves melody/rhythm, changes timbre	Same genre, different voice
0.8-1.0	Close to source — minimal changes, mostly regeneration	Voice swap, subtle tweaks

Parameters

Parameter	Flag	Default	Description
Source audio	`--src-audio`	required	Path to reference audio file
Caption	`--caption` / `-c`	`""`	New style description
Lyrics	`--lyrics` / `-l`	`""`	New lyrics (optional)
Cover strength	`--cover-strength`	0.5	Noise preservation (0.0=pure noise/reimagine, 1.0=closest to source)
Quality	`--quality`	standard	draft/standard/high/max
Format	`--format`	flac	Output audio format

Reference Audio Tips

Supported formats: MP3, WAV, FLAC, OGG, AAC, M4A
Optimal length: Match your target duration (model uses the full reference)
Quality matters: Higher quality reference = better style extraction
Loudness: Normalize reference to ~-14 LUFS for consistency