Pocket Theory: Chords & Scales

Tap any chord, scale or key to open it and keep exploring. Tap the notes you're holding to name the chord, or tune up with the built-in tuner.

The music theory app you can wander through. Every scale, chord and mode, and how they connect.

TAP ANYTHING TO EXPLORE IT Every chord, scale, key and note you see opens with one tap. Open a chord and see the keys it lives in, the scales built around it and what to swap it for. Tap any of them and keep going: from a chord to its key, to a mode, to the one note that gives the mode its sound. Start anywhere and follow your curiosity.

CHORD FINDER Tap the notes you're holding on the piano or the guitar neck. Pocket Theory names the chord, shows the chords one note away, and lists every scale those notes fit. Each answer opens its own page. Found a chord you like? Save it and give it a name.

A TUNER THAT LISTENS Tune your guitar, bass, voice or any instrument through the microphone. The chromatic tuner shows the note, how many cents sharp or flat you are, and which way to go. Tuning to something other than A = 440? Change the reference pitch.

GUITAR CHORD SHAPES With the guitar on, chord pages show playable shapes for that chord, worked out for every root. Swipe through them and tap one to hear it strummed.

HEAR WHAT MAKES A MODE Hold a drone under any mode and play it over the top, then compare it with the scale it comes from. The notes that give it its sound are held and lit as they play.

EVERY KEY, EVERY CHORD IN IT Key pages show the chords of the key and what each one does: home, leads away, pulls home. Secondary dominants, borrowed chords, and twelve progressions to play. Every scale names its relative and parallel major or minor.

PROGRESSION BUILDER Pick a key and tap chords to build a progression: the key's own chords, borrowed chords and secondary dominants, or start from a classic like the 12-bar blues. Loop it at your tempo, see each chord on the piano or guitar as it plays, and save it with a name.

66 SCALES, 42 CHORDS, EVERY ROOT Major and its modes, melodic and harmonic minor, pentatonics, blues, bebop and scales from around the world. Triads to thirteenths, with their inversions. Each comes with a short line on how it sounds and where you'll hear it.

PIANO OR GUITAR See it all on a keyboard, a fretboard or an upright neck, with note names or scale degrees. Left-handed guitar included.

SAVE, SEARCH, SHARE Star any page to keep it, search by name, and pick up again from Recently opened. Share any page as a link: it opens in a web browser, no app needed.

MAKE IT YOURS Choose which sections show, fold away or hide on each kind of page. Two layouts, six looks and 42 color palettes.

IN YOUR POCKET The tuner, a metronome and tap tempo are one tap away on every page. Sound plays with the silent switch on. Works offline, with no account.