About RealMusicTheory
A free, open music-theory textbook — with examples drawn from the composers you love.
What this is
RealMusicTheory is a complete, freely available music-theory curriculum covering 108 chapters across 11 units — from the fundamentals of notation and rhythm all the way through chromaticism, jazz harmony, twentieth-century techniques, and twelve-tone serialism. Every lesson is written to be read independently, without a teacher or course enrollment.
The distinguishing feature is personalization: the harmony examples are not generic textbook constructions. Each one is a real passage from the repertoire, chosen because it clearly illustrates the concept being taught. Pick your favorite composers at the top of the page, and wherever a matching passage exists, the example becomes one from your selection.
How the composer swap works
Every harmony lesson that supports examples is linked to one or more musical concepts — things like "Neapolitan sixth chord" or "cadential 6/4." Behind the scenes, a corpus of human-annotated scores has been cross-referenced against those concepts: we know, for instance, that a particular bar of a Chopin mazurka contains a textbook Neapolitan sixth in context.
When you load a lesson, the site checks which composers you have selected and pulls an example from one of theirs when available. The notation is rendered in the browser and you can hear it play back. If no passage has been verified for your selected composers yet, the lesson falls back to a canonical Bach chorale example (the most comprehensively annotated corpus in the dataset).
All examples are drawn from public-domain scores — no copyrighted modern editions, only historically verified public-domain manuscripts and early prints.
Sourcing and credits
The curriculum structure and harmony lesson content are adapted from Open Music Theory (OMT), edited by Chelsey Hamm and Mark Gotham, published under a Creative Commons Attribution–ShareAlike 4.0 (CC BY-SA 4.0) license. RealMusicTheory inherits that license for its prose content: you are free to adapt and redistribute with attribution and the same license.
Musical examples are drawn from two open, human-annotated corpora:
- The DCML corpora — a growing collection of annotated scores maintained by the Digital and Cognitive Musicology Lab at EPFL, covering Romantic and Classical piano and chamber repertoire.
- The When-in-Rome corpus — a large-scale dataset of Roman-numeral analyses of Bach chorales and other tonal works, used here primarily for the Bach chorale examples that appear throughout the harmony chapters.
Score rendering is done in the browser using open-source notation libraries against the MusicXML files distributed with these corpora.
Composer portraits are public-domain works via Wikimedia Commons.
Part of a suite
RealMusicTheory is one piece of a broader set of open music-education tools:
- Stave — a sight-reading trainer that imports MusicXML scores and drills notes, intervals, harmony, and rhythm from your own repertoire.
- RealEarTrainer — an ear-training app with chord recognition, Spotify integration, and AI-powered transcription, available on iOS and the web.
A work in progress
This project is actively developing. More composers are being added to the example corpus as annotations are verified; more chapters are being connected to the swap system; and the playback and notation rendering are continually improving. If you find an error in a lesson, a broken example, or a concept that deserves a better passage — feedback is welcome.
The full chapter list is on the home page. Chapters marked with a ★ examples badge already have composer-swappable passages. Unlabeled chapters contain prose and notation without the swap feature yet.