How much does Theory Toolkit cost?

Nothing. Now or later. This web app is free to use and share and will remain that way as it continues to grow. No account, email address, or payment information is required.

Explore Theory Toolkit

Theory Toolkit is a visual companion for music students and instructors. It is designed to make musical relationships easier to see during a lesson and easier to revisit while practicing or reviewing.

New to Theory Toolkit?

Start with Fretboard Explorer to explore note locations on Guitar, Lap Steel, or Bass; use Chord Shape Explorer for beginner chord fingerings; or open Progression Explorer to see how familiar chords move together.

Choose an Explorer

Open any Explorer below and begin experimenting with its controls.

Fretboard Explorer Updated

Explore note locations on Guitar, Lap Steel, and Bass with instrument-specific tunings and artwork, direct string selection, note filtering, enharmonic labels, Focus, and instrument details.

Chord Shape Explorer New Feature

Explore beginner open-chord shapes, chord tones, editable fingerings, open and muted strings, and teacher-directed Focus.

Scale Explorer

Explore major and minor diatonic, pentatonic, and blues scales across the fretboard or within five familiar shapes.

Key Explorer New Feature

Explore major-key scales, diatonic chords, triad construction, harmonic roles, and common chord movement.

Progression Explorer New Feature

Explore beginner-friendly common progressions, translate Roman-numeral patterns into every major key, and see why familiar chord movements work.

Modes Explorer New Feature

Compare parallel modes with the Major scale on the same tonic, see which notes change, and connect each mode to its parent Major scale.

Help improve Theory Toolkit

Theory Toolkit is actively evolving. The current Explorers are ready to use, and feedback from students, players, and instructors is welcome.

Please explore freely. Change selections, try combinations, and see whether each page behaves the way you expect it to.

The feedback I am most interested in is:

You do not need to be a music-theory expert to give useful feedback. If something does not make sense, that itself is useful information. Instructors and experienced players are also encouraged to identify anything musically misleading or anything they would present differently to a student.

Theory Toolkit is a teaching supplement. It does not replace an instructor or independently teach music theory.