Music Theory by Justin Guitar

Music Theory by JustinGuitar makes music theory practical, interactive, and guitar-focused. Learn keys, scales, notes, chords, and progressions through bite-sized lessons and hands-on fretboard exercises—not abstract diagrams or passive videos.

Build fretboard knowledge, recognize patterns, learn songs by ear, join jams confidently, and create your own riffs and music. The app includes progressive exercises, immediate feedback, and a fretboard trainer designed for learning at your own pace. Full access to all published stages is available through subscription plans from Justin Sandercoe, the teacher behind the trusted JustinGuitar platform.