Chord Analyzer Skill

---

name: chord-analyzer

description: "Analyze music audio files to extract chord progressions, key signature, tempo, and song structure. Use when user wants to identify chords, analyze a song's harmony, or extract musical information from audio files (mp3, wav, m4a, etc.)."

homepage: https://github.com/librosa/librosa

metadata: { "openclaw": { "emoji": "🎸", "requires": { "bins": ["python3"], "pip": ["librosa", "numpy"] } } }

---

# Chord Analyzer Skill

Analyze music audio files to extract chord progressions, key signature, tempo, and song structure.

When to Use

✅ **USE this skill when:**

When NOT to Use

❌ **DON'T use this skill when:**

Supported Formats

Installation

First time use requires installing dependencies:

pip3 install librosa numpy scipy scikit-learn soundfile

Usage

Basic Analysis

# Analyze an audio file
python3 chord_analyzer.py

# Edit the script to change the audio path
# Default: /Users/chentiewen/Music/网易云音乐/example.mp3

Script Integration

Copy the `chord_analyzer.py` script to your workspace and modify the `audio_path` variable:

audio_path = "/path/to/your/song.mp3"
result = analyze_audio(audio_path)

Output

The analyzer provides:

1. **Key Signature**: Detected musical key (e.g., C, F#m, G)

2. **Tempo**: Speed in BPM with rhythm classification

3. **Chord Progression**: Complete chord sequence with timestamps

4. **Chord Statistics**: Most frequently used chords

5. **Song Structure**: Intro/Verse/Outro segmentation (basic)

Sample Output

调性: F#m
速度: 123.0 BPM
节奏: 快板 (Allegro)

和弦走向:
F#mdim → A → D → Bm → E → A → D → Bm → E ...

主要和弦:
  A: 15次 (20.3%)
  E: 14次 (18.9%)
  D: 12次 (16.2%)

How It Works

1. **Load Audio**: Uses `librosa.load()` to read audio at 22.05kHz

2. **Extract Chroma**: Computes chroma features (pitch class profiles) using STFT

3. **Detect Key**: Analyzes chroma energy across all 12 keys (major + minor)

4. **Track Tempo**: Uses `librosa.beat.beat_track()` for tempo detection

5. **Analyze Chords**: Samples chroma at measure boundaries and matches against chord templates

6. **Merge & Simplify**: Combines consecutive identical chords

Limitations

For Complete Transcription

For professional music transcription, recommend:

Notes