🎵 Voice Note to MIDI

Transform your voice memos, humming, and melodic recordings into clean, quantized MIDI files ready for your DAW.

What It Does

This skill provides a complete audio-to-MIDI conversion pipeline that:

1. Stem Separation - Uses HPSS (Harmonic-Percussive Source Separation) to isolate melodic content from drums, noise, and background sounds
2. ML-Powered Pitch Detection - Leverages Spotify's Basic Pitch model for accurate fundamental frequency extraction
3. Key Detection - Automatically detects the musical key of your recording using Krumhansl-Kessler key profiles
4. Intelligent Quantization - Snaps notes to a configurable timing grid with optional key-aware pitch correction
5. Post-Processing - Applies octave pruning, overlap-based harmonic removal, and legato note merging for clean output

Pipeline Architecture

Audio Input (WAV/M4A/MP3)
    ↓
┌─────────────────────────────────────┐
│ Step 1: Stem Separation (HPSS)     │
│ - Isolate harmonic content          │
│ - Remove drums/percussion           │
│ - Noise gating                      │
└─────────────────────────────────────┘
    ↓
┌─────────────────────────────────────┐
│ Step 2: Pitch Detection             │
│ - Basic Pitch ML model (Spotify)    │
│ - Polyphonic note detection         │
│ - Onset/offset estimation           │
└─────────────────────────────────────┘
    ↓
┌─────────────────────────────────────┐
│ Step 3: Analysis                    │
│ - Pitch class distribution          │
│ - Key detection                     │
│ - Dominant note identification      │
└─────────────────────────────────────┘
    ↓
┌─────────────────────────────────────┐
│ Step 4: Quantization & Cleanup      │
│ - Timing grid snap                  │
│ - Key-aware pitch correction        │
│ - Octave pruning (harmonic removal) │
│ - Overlap-based pruning             │
│ - Note merging (legato)             │
│ - Velocity normalization            │
└─────────────────────────────────────┘
    ↓
MIDI Output (Standard MIDI File)

Setup

Prerequisites

• Python 3.11+ (Python 3.14+ recommended)
• FFmpeg (for audio format support)
• pip

Installation

Quick Install (Recommended):

cd /path/to/voice-note-to-midi
./setup.sh

This automated script will:

• Check Python 3.11+ is installed
• Create the ~/melody-pipeline directory
• Set up the virtual environment
• Install all dependencies (basic-pitch, librosa, music21, etc.)
• Download and configure the hum2midi script
• Add melody-pipeline to your PATH

Manual Install:

If you prefer manual setup:

mkdir -p ~/melody-pipeline
cd ~/melody-pipeline
python3 -m venv venv-bp
source venv-bp/bin/activate
pip install basic-pitch librosa soundfile mido music21
chmod +x ~/melody-pipeline/hum2midi

5. Add to your PATH (optional):

echo 'export PATH="$HOME/melody-pipeline:$PATH"' >> ~/.bashrc
source ~/.bashrc

Verify Installation