Simple online theory lessons and exercises presented as short videos. This is much like Kahn Academy for music.

Ear Training On The Run is a series of audio courses designed to teach musicians and aspiring musicians to identify, solely by hearing, intervals, chords, rhythms and other basic elements of music

Music theory tutorials on clefs, key and time signatures, scales, chords, and more.

The Interactive Circle of Fifths ("the Circle" for short) is a tool designed to help musicians to: (a) figure out the key of a piece of music, (b) easily transpose music to a different key, (c) compose new music, and (d) understand key signatures, scales, and modes.

A selected list of web-based music teaching and creation resources.

A web site for music theory and ear training. Can be used online or downloaded.

eMusicTheory.com provides online tools for teachers and students of basic music theory, everywhere.

Welcome to the 8notes.com online Music Theory course. 46 Lessons introducing you to the most important concepts of music theory.