Music Theory

Want to hear it and play it yourself? See the I–V–vi–IV chord progression in every key on PlayTheory, and play...

Ready to hear the theory in action? Explore scales, keys and chords hands-on in PlayTheory's free music theory reference.

Build one yourself: play the C major chord on an interactive piano at PlayTheory, then explore the other chord types.

Train your ear: listen to and play every musical interval, from a minor second to an octave, on PlayTheory.

See relative keys side by side: compare the key of C major with its relative, the key of A minor,...

Want to try it yourself? Play the A minor scale on an interactive piano at PlayTheory, and hear how it...

Want to try it yourself? Play the C major scale on an interactive piano at PlayTheory, and hear every note...

  Exploring the 12-Note Pattern: The Foundation of MusicWelcome to another insightful lesson from the Guitar Theory Simplified series! In...