Apple Music-Style Automix Script

Create seamless DJ-style mixes from a folder of audio tracks, mimicking Apple Music's Automix feature with intelligent transitions, tempo matching, and crossfading.

Features

🎵 Smart Track Analysis

• Automatic tempo detection
• Key detection for harmonic mixing
• Energy level analysis
• Spectral feature analysis

🔄 Intelligent Transitions

• Equal-power crossfading
• Tempo adjustment for better transitions
• Track reordering for optimal flow
• Compatibility scoring between tracks

🎛️ Professional Mixing

• Configurable crossfade duration
• Audio normalization
• Support for multiple audio formats
• High-quality output

Installation

1. Clone or download this script
2. Install Python dependencies:

   pip install -r requirements.txt

Supported Audio Formats

• MP3
• WAV
• FLAC
• M4A
• AAC
• OGG

Usage

Basic Usage

python automix.py /path/to/your/music/folder

Advanced Options

python automix.py /path/to/music -o "my_mix.wav" -c 6.0 -s 48000

Command Line Arguments

Argument	Description	Default
input_folder	Path to folder containing audio tracks	Required
-o, --output	Output filename	automix_output.wav
-c, --crossfade	Crossfade duration in seconds	8.0
-s, --sample-rate	Sample rate for processing	44100

Examples

Create a mix with default settings:

python automix.py ~/Music/MyPlaylist

Create a mix with custom crossfade and output name:

python automix.py ~/Music/PartyMix -o "party_night_mix.wav" -c 10.0

High-quality mix with longer crossfades:

python automix.py ~/Music/ChillOut -o "chill_mix.wav" -c 12.0 -s 48000

How It Works

1. Audio Analysis

The script analyzes each track for:

• Tempo (BPM): For beat-matching
• Musical Key: For harmonic compatibility
• Energy Level: For smooth energy transitions
• Spectral Characteristics: For timbral matching

2. Smart Ordering

Tracks are automatically reordered using a compatibility algorithm that considers:

• Tempo similarity
• Key relationships (circle of fifths)
• Energy level progression
• Spectral characteristics

3. Seamless Transitions

• Equal-power crossfading: Maintains consistent volume
• Tempo adjustment: Slight tempo changes for better sync
• Beat alignment: Crossfades happen at musical boundaries
• Audio normalization: Prevents clipping and volume jumps

Output

The script creates:

• A single mixed audio file with all tracks seamlessly blended
• Detailed logging showing the mixing process
• Compatibility scores for each transition

Tips for Best Results

📁 Organize Your Music

• Use tracks from similar genres for best results
• Ensure good audio quality (avoid heavily compressed files)
• Include 4-8 tracks for optimal mix length

🎵 Track Selection

• Similar BPM ranges work best (±20 BPM)
• Tracks in related keys create smoother transitions
• Consider energy progression (start calm, build energy, wind down)

⚙️ Settings Optimization

• Short crossfades (4-6s): For energetic, quick mixes
• Long crossfades (10-15s): For ambient, chill mixes
• Higher sample rates: For audiophile-quality output

Troubleshooting

Common Issues

"No audio files found"

• Check that your folder contains supported audio formats
• Verify folder path is correct

"Error analyzing [filename]"

• File may be corrupted or in unsupported format
• Try with different audio files

Memory issues with large files

• Process smaller batches of tracks
• Use lower sample rates for testing

Performance Tips

• Use WAV/FLAC for best quality
• Limit to 10-15 tracks per mix for reasonable processing time
• Close other applications if memory usage is high

Technical Details

Dependencies

• librosa: Audio analysis and processing
• soundfile: Audio file I/O
• numpy: Numerical computations
• scipy: Signal processing

Algorithm Overview

1. Feature Extraction: Extract musical features from each track
2. Compatibility Matrix: Calculate transition scores between all track pairs
3. Optimal Ordering: Use greedy algorithm to find best track sequence
4. Crossfade Generation: Create smooth transitions with equal-power curves
5. Final Assembly: Combine all tracks with transitions into final mix

License

This script is provided as-is for educational and personal use. Ensure you have rights to the audio files you're processing.

Contributing

Feel free to improve the script by:

• Adding more sophisticated beat-matching
• Implementing different crossfade curves
• Adding support for more audio formats
• Improving the track ordering algorithm

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Enjoy creating professional-quality mixes with the power of Python! 🎧