Amadeus - Automatic Chord Recognition in iOS
Important
Amadeus is an iOS application designed for musicians to analyse recorded or uploaded audio, retrieve chord progressions, estimate musical keys, and explore a comprehensive music theory library. The system combines a SwiftUI frontend with a Python analysis server utilising DSP and machine learning techniques for chord recognition.
Note
Development Timeline: Started early August 2025 • Current Version: December 2025 • Future Roadmap: 2026+
Key Features
User Features
Audio Analysis: Load audio files or record up to 30 seconds for analysis
Chord Timeline: Visual timeline with chord progressions, smoothing, and confidence metrics
Key Estimation: Automatic detection of musical key and mode
Transposition: Transform detected chords to different keys
Music Theory Library: Comprehensive chord types, scales, and progressions
Export Options: Share analysis results and export to MIDI (planned)
Technical Features
Hybrid Architecture: SwiftUI iOS app with Python FastAPI backend
ML-Based Analysis: Leverages Spotify’s Basic Pitch model for note detection
Chord Assembly: Sophisticated algorithm for deriving chords from note events
Confidence Scoring: Weighted confidence metrics for detected chords
Smoothing Filters: Temporal smoothing for stable chord detection
Quick Links
Quickstart - Get started with Amadeus
System Architecture - System architecture overview
iOS App Structure - iOS app documentation
API Reference - Server API reference
Development Roadmap - Development roadmap