The circle of fifths: every key on one circle
The circle of fifths arranges the twelve keys so that each one is a perfect fifth from its neighbor. Going clockwise adds a sharp at each step, and going counterclockwise adds a flat. Once you know how to read it, it answers three questions at a glance: which key signature goes with which key, what the relative minor is, and which keys are closely related. Let's build it together, and then you'll try it out.
Clockwise: add a sharp (up a fifth). Counterclockwise: add a flat (down a fifth). At the bottom, enharmonic keys join the two branches.
- Key signature
- no sharps or flats
- Relative
- A minor, a minor third below; leading tone G♯ added as an accidental
- Closely related keys
- A minor, F major, G major, D minor, E minor
- Landmark
- the model scale, no accidentals
How the circle is built
Let's start from C major, at the top, with no sharps or flats. Go up a perfect fifth, that is, five letter names, C, D, E, F, G, and you reach G major, which has one sharp. A fifth higher, you reach D major, with two sharps. Keep going clockwise and you get A, E, B, F♯ and C♯. Now go the other way, down by fifths: each step adds a flat, and you get F, B♭, E♭, A♭, D♭, G♭ and C♭.
At the bottom of the circle, the two paths meet. F♯ major, with six sharps, and G♭ major, with six flats, sound the same on a piano. They're called enharmonic keys, and so are B and C♭, and C♯ and D♭.
| Key signature | Accidentals | Major | Relative minor |
|---|---|---|---|
| none | C major | A minor | |
| 1 sharp: F♯ | G major | E minor | |
| 2 sharps: F♯, C♯ | D major | B minor | |
| 3 sharps: F♯, C♯, G♯ | A major | F♯ minor | |
| 4 sharps: F♯, C♯, G♯, D♯ | E major | C♯ minor | |
| 5 sharps: F♯, C♯, G♯, D♯, A♯ | B major | G♯ minor | |
| 6 sharps: F♯, C♯, G♯, D♯, A♯, E♯ | F♯ major | D♯ minor | |
| 7 sharps: F♯, C♯, G♯, D♯, A♯, E♯, B♯ | C♯ major | A♯ minor | |
| 1 flat: B♭ | F major | D minor | |
| 2 flats: B♭, E♭ | B♭ major | G minor | |
| 3 flats: B♭, E♭, A♭ | E♭ major | C minor | |
| 4 flats: B♭, E♭, A♭, D♭ | A♭ major | F minor | |
| 5 flats: B♭, E♭, A♭, D♭, G♭ | D♭ major | B♭ minor | |
| 6 flats: B♭, E♭, A♭, D♭, G♭, C♭ | G♭ major | E♭ minor | |
| 7 flats: B♭, E♭, A♭, D♭, G♭, C♭, F♭ | C♭ major | A♭ minor |
The order of sharps and flats
Sharps are always added in the same order: F, C, G, D, A, E, B. Flats come in the reverse order: B, E, A, D, G, C, F. Notice that each new accidental is itself a fifth from the previous one. That's why the circle and the order of accidentals tell the same story.
Relative minors
Every major key shares its key signature with a minor key, called its relative minor, which lies a minor third lower. A minor goes with C major, E minor with G major, and D minor with F major. Most charts show the minor keys as an inner ring, each one facing its relative major.
How musicians use it
- Read key signatures instantly, because the number of accidentals tells you the position on the circle.
- Find closely related keys: neighbors differ by only one accidental, which is why music modulates to them so easily.
- Understand chord progressions: many of them move by fifths toward the tonic. D minor, G, then C, which is ii, V, I in C major, is a good example, and it's the backbone of jazz harmony.
- Transpose: moving to a neighboring key changes only a few notes, while moving across the circle changes almost all of them.
Method: with sharps, the major tonic is a half step above the last sharp; with flats, it is the second-to-last flat (F major for one flat). The relative minor is a minor third lower.