Rust Music Semantics

A music theory library focused on precision, correctness, and expressiveness.

This library provides:

1. A powerful music theory engine, with precise types appropriate for all manner of situations.
2. Functions for inferring chord/scale spellings and names, as well as parsing chord/scale names into sets of notes.
3. A means of converting Rust types to Lilypond or VexTab source code, allowing for automated document generation or application development.

General Use Cases for this Library:

• Tonal analysis and general music theory computation -- answering questions like which chords or scales fit into which others, finding voiceleading paths between chords, finding symmetries, iterating through the various possible voicings of a chord, parsing or generating chord/scale names, etc. Functions for answering all of these questions exist out-of-the-box.
• Automated scoring -- Output lilypond source code for document generation, or VexTab for integration with JS frontends.
• Application development -- VexTab is a powerful way to generate music notation in a UI. Using Web Assembly, Rust is easy to incorporate into browser-based frontend frameworks.

Code Examples

See the music/examples directory for some demonstrations on the basic types.

Philosophy

This crate takes much influence from Dmitri Tymoczko's work, which you can find in his book Geometry of Music.

In addition, it endeavours to achieve the following:

• Create a type system that enforces clear musical intent while remaining ergonomic.
• Code solutions for sound music-theoretic inference, deduction, and search.
• Solutions that apply over combinatorically complete spaces of musical possibilities.
• Mathemetically precise types that account for the various gradations of information one might have available.
• Easy-to-use API for converting musical objects into engraved notation.

TODO

• Chord types as enums -- FiveNoteChordQuality, SixNoteChordQuality, IrregularScaleQuality
• Various geometric calculations of sub-/super-chords, etc.
• Chord name parsing (regex)
• Melodic Sequencer
• PcSet vs PcMultiset
• Do a pass on ergonomics
• Common scale check -- Check which common scales a chord fits into.

VexTab TODO

• Tuplets

Lilypond TODO

• Repeat blocks
• Breaks, barlines,
• Modifiers like \hide, \stemUp, \stemDown, etc
• Context blocks (create a lazy static Slashes context for a useful example)
• Chord name customization
• Chord diagrams, custom naming and fingerings