Every key, every connection — in one shape.
Clicking a key on the circle shows the scale of that key on the staff, on the piano keyboard and on the guitar fretboard at the same time, and plays the tonic chord. The buttons marked Autumn Leaves and Giant Steps move around the circle one chord at a time, so that the harmonic path of each tune can be followed while it sounds.
The circle of fifths is an arrangement of the twelve keys in which every step clockwise rises a perfect fifth and adds one sharp to the key signature, and every step anticlockwise rises a perfect fourth and adds one flat. Two keys that sit next to each other on the circle share all of their notes but one, which is why the shape also shows which keys — and which chords — sound closely related.
Click a key
Choose any position on the circle. The outer ring holds the twelve major keys, and the inner ring holds the relative minor of each major key.
Three views of one key
The three panels below show the same scale in three forms: written on the staff, laid out on the piano keyboard, and marked on the guitar fretboard. Use the panel that matches the instrument being played.
Staff
Keyboard
Guitar fretboard (standard tuning, frets 0–12)
What the circle shows
One step around the circle changes the key signature by one accidental
Moving one step clockwise adds one sharp to the key signature, and moving one step counter-clockwise adds one flat. The order of the positions around the circle is therefore the order of the key signatures. C major has no sharps and no flats, G major has one sharp (F♯), D major has two (F♯ and C♯), and the count continues clockwise as far as F♯ major with six sharps; counter-clockwise, F major has one flat and the count continues as far as D♭ major with five flats. The circle displays the order in which sharps and flats are added. The two directions meet on the far side of the circle, where the same set of pitches can be written either as C♯ major with seven sharps or as D♭ major with five flats, which is the point at which the circle changes from sharp spelling to flat spelling.
The dominant of a key stands one step clockwise
Moving one step clockwise means moving up a perfect 5th. The dominant chord of a key therefore stands one position clockwise from that key: G is the dominant of C, D is the dominant of G, and A is the dominant of D. A V → I resolution is one step counter-clockwise on the circle, from the dominant back to the tonic. A ii-V-I in C major is Dm7 → G7 → Cmaj7, and the roots of those three chords, D, G and C, occupy three adjacent positions, so each chord moves one step counter-clockwise.
The relative minor stands on the inner ring
Every major key shares its key signature with the minor key whose tonic is three semitones below it, and the circle places that minor key on the inner ring directly beneath the major key. C major and A minor contain the same seven notes, and the difference between them is which of those notes acts as the tonic. Click a major key, then click the segment beneath it, and the same seven notes sound with a different tonic.
The three tonics of the Coltrane changes
The Coltrane changes, used in "Giant Steps", "Countdown" and "26-2", move through three tonal centers a major third apart: B, G and E♭. Those three keys stand four positions apart on the circle, and the order the tunes use, B → G → E♭, moves four positions counter-clockwise each time. A progression that is hard to hear therefore has a simple description on the circle: the same distance three times, arriving back at the starting key. Press Giant Steps above to follow the path.
Written drill — key signatures
The drill asks four things: how many sharps or flats a key signature contains, which key carries a given signature, which major and minor keys are paired as relatives, and which accidental is written last in a signature. Every question comes from the circle above. The score and the streak are saved between visits.