I built a free, browser-based tool for exploring scales, modes, and their diatonic chords. Pick any root note and scale (major, natural minor, all seven modes, and 70+ other scales) and instantly see which chords (triads, 7th, 9th, etc.) belong to that key.

It also includes a built-in sequencer so if you've found interesting chords for your scale, you can arrange them into a progression and hear how they flow together. No need to switch between a theory reference and a DAW just to test whether a ii–V–I sounds right in your preferred scale.

No signup, no ads, no paywall, just a tool I wished existed when I was learning music theory. There's also a growing collection of articles covering diatonic chords, seventh chords, modes, extended jazz harmony, and common progressions.

Built with Hugo as a static site. Would love feedback from fellow musicians and music theory nerds.