C major · Quarter notes
Guitar music is written an octave higher than it sounds, so the playback is at real guitar pitch.
Tap any note or chord to hear it. Play counts you in for one measure. Keys: space plays or stops, N makes a new exercise, T shows or hides the tab.
The backing track is 12-bar blues: drums, a boogie bass line, and organ. Quick change moves to the IV chord in bar 2. Major I–IV uses the same band on a two-bar loop: one bar of the I chord, one of the IV. Play counts you in for one measure, then loops until you stop it.
Orange dots are the root. With Chord tones on, notes of the chord being played get a blue ring while the track runs, so you can aim for them as the chords change. Chord tones that aren't in the scale (like the IV chord's major 3rd over minor pentatonic) show as hollow blue dots, labeled by their part in the chord: R, 3, 5 or ♭7. Pick Modes to play the seven modes: tap Ion, Dor, Phr, Lyd, Mix, Aeo or Loc. Each mode's color note (the one that gives it its sound, like Dorian's 6 or Lydian's ♯4) has a purple ring, and the backing switches to a Drone on the root (you can pick the blues under Track instead). Over the drone, Chord tones rings the mode's home chord while it plays. Tap a chord beside Chord tones to see its tones any time (tap it again to go back to following the track); the chord being played is outlined in blue. Tap a dot to hear it. Space plays or stops.
Pick a chord and any three strings. The fretboard shows every playable way to play that triad on those strings, up and down the neck: one note on each string, joined by a line colored by inversion. Root position has the root on the lowest of the three strings; 1st inversion has the 3rd there; 2nd inversion has the 5th. Tap the inversion buttons to show or hide each kind.
Tap a shape's line to hear the chord, or a dot to hear one note. Play (or space) strums every shape in order up the neck. Pick up to three strings; with one or two, the fretboard shows where the chord's notes are on them.
Shell chords are three notes: the root, the 3rd and the 7th (or the 6th), with the 5th left out. They're the jazz player's go-to comping shapes. The fretboard shows every shell for the chord you pick, one note per string on three neighbouring strings, with any of the three notes in the bass. The extended shells (9, 11, 13 and altered) leave the root out, the usual jazz way: the 3rd, the 7th and the extension, with the bass player covering the root. Each is written in notation underneath.
Pick a root and a chord type. The fretboard shows that chord's shapes from two chord books, moved to the root you picked, with each one written in notation underneath. Most have the root in the bass; some have another chord tone there, and a few leave the root out (where the book marks it, its place is a dashed circle).
One voicing at a time is shown in colour (strings without a coloured dot aren't played); the others are greyed out. Tap a grey shape (or its chord in the notation) to switch to it and hear it. Play (or space) steps through them all.