MusicTheory Documentation

Welcome to the MusicTheory library documentation. This comprehensive C# library provides immutable domain objects for music theory concepts, built with modern .NET practices and extensive test coverage.

What is MusicTheory?

MusicTheory is a powerful .NET library that models music theory concepts as code. Whether you're building a music education app, a composition tool, or analyzing musical structures, this library provides the fundamental building blocks you need.

Key Features

Notes: Create and manipulate musical notes with support for all alterations
Intervals: Calculate musical intervals with proper quality handling
Scales: Generate scales with 15+ scale types including modal and exotic scales
Chords: Build chords with 40+ types including triads, seventh chords, extended, altered, and suspended chords
Key Signatures: Handle key signatures with circle of fifths navigation

Transposition: Transpose notes, chords, and scales by intervals
Chord Progressions: Roman numeral analysis and common progressions
MIDI Integration: Convert between notes and MIDI numbers
Enharmonic Equivalence: Handle enharmonic relationships (C# ↔ Db)
Time & Rhythm: Time signatures and note duration calculations

Immutable Objects: Thread-safe, predictable behavior
Fluent API: Chainable method calls for readable code
Type Safety: Strong typing prevents invalid music theory constructs
Performance: Lazy evaluation and calculated properties
Comprehensive Testing: 479+ unit tests ensure reliability

Quick Example

Here's a simple example demonstrating the library's capabilities:

using MusicTheory;

// Create a note
var c4 = new Note(NoteName.C, Alteration.Natural, 4);

// Build a chord
var cMaj7 = new Chord(c4, ChordType.Major7);

// Get chord notes
var notes = cMaj7.GetNotes(); // C, E, G, B

// Get chord symbol
var symbol = cMaj7.GetSymbol(); // "Cmaj7"

// Create a scale
var cMajorScale = new Scale(c4, ScaleType.Major);
var scaleNotes = cMajorScale.GetNotes(); // C, D, E, F, G, A, B, C

Installation

Getting Started

Clone the repository:
git clone https://github.com/phmatray/MusicTheory.git cd MusicTheory
Build the solution:
dotnet build
Run tests to verify everything is working:
dotnet test

Where to Start?

Getting Started Guide - Learn the basics of the library
Working with Notes - Understanding the Note class
Building Chords - Create and manipulate chords
Scale Generation - Generate and work with scales
API Reference - Complete API documentation

Requirements

.NET 9.0 or later
Any IDE with C# support (Visual Studio, Rider, VS Code)

Support

14 June 2025