The circle of fifths is a diagram that arranges the 12 major keys in a circle, each one a perfect 5th away from the next. At a glance it shows how many sharps or flats each key signature has, which keys are neighbors and what the relative minor of each major key is. It is one of the most useful reference tools in music theory.
How to read the circle of fifths
Reading the diagram follows four simple rules:
- C major at the top (no accidentals). This is the starting point.
- Clockwise = sharps. Each step to the right goes up a perfect 5th and adds one sharp: G (1), D (2), A (3), E (4), B (5), F♯ (6).
- Counterclockwise = flats. Each step to the left goes down a perfect 5th (or up a perfect 4th) and adds one flat: F (1), B♭ (2), E♭ (3), A♭ (4), D♭ (5).
- Inner ring = relative minors. Under each major key is its relative minor, which shares the same key signature: A minor under C major, E minor under G major, and so on.
At the bottom, the keys with six accidentals are enharmonic: F♯ major (6 sharps) sounds the same as G♭ major (6 flats). That is why the circle "closes" on itself: after twelve fifths you are back at the starting point.
What the circle of fifths is for
It is not just a pretty diagram: it is a practical tool used every day in harmony and composition.
It also helps your ear: when you recognize a key by ear you have to name it and know its key signature, and the circle is the quickest way to remember them. You can practice with the listening exercises recognize the major key, recognize the minor key and, with both modes mixed, recognize the key: major and minor.
- Remembering key signatures. You can tell at once how many sharps or flats any key has, without memorizing them one by one. To write them on the staff, follow the order of the accidentals in the key signature.
- Finding closely related keys. The keys next to each other on the circle (and their relatives) are the closely related keys: they share almost their whole key signature and are the ones you modulate to most naturally.
- Finding the relative minor. Useful for moving from a major key to its relative minor without changing the key signature.
- Understanding progressions by fifths. Many progressions, starting with the V–I cadence and the ii–V–I turnaround, move around the circle. The motion from the dominant to the tonic is precisely a step of a fifth.
Key signature chart for all keys
This table summarizes what the circle shows: each major key, its relative minor and the accidentals of its key signature. It answers questions such as "which key has three sharps?" or "which key has two flats?"
| Key signature | Major key | Relative minor | Accidentals |
|---|---|---|---|
| 0 | C major | A minor | — |
| 1 ♯ | G major | E minor | F♯ |
| 2 ♯ | D major | B minor | F♯ C♯ |
| 3 ♯ | A major | F♯ minor | F♯ C♯ G♯ |
| 4 ♯ | E major | C♯ minor | F♯ C♯ G♯ D♯ |
| 5 ♯ | B major | G♯ minor | F♯ C♯ G♯ D♯ A♯ |
| 6 ♯ | F♯ major | D♯ minor | F♯ C♯ G♯ D♯ A♯ E♯ |
| 7 ♯ | C♯ major | A♯ minor | all 7 sharps |
| 1 ♭ | F major | D minor | B♭ |
| 2 ♭ | B♭ major | G minor | B♭ E♭ |
| 3 ♭ | E♭ major | C minor | B♭ E♭ A♭ |
| 4 ♭ | A♭ major | F minor | B♭ E♭ A♭ D♭ |
| 5 ♭ | D♭ major | B♭ minor | B♭ E♭ A♭ D♭ G♭ |
| 6 ♭ | G♭ major | E♭ minor | B♭ E♭ A♭ D♭ G♭ C♭ |
| 7 ♭ | C♭ major | A♭ minor | all 7 flats |
How to memorize the circle of fifths
There are classic tricks that save you from memorizing the diagram:
- The order of sharps is F - C - G - D - A - E - B. Each new key with sharps adds the next one on the list.
- The order of flats is the reverse: B - E - A - D - G - C - F.
- To find the major key from a sharp key signature, go up a half step (UK: semitone) from the last sharp (with three sharps, the last is G♯ → A major). With flats, the key is the second-to-last flat (with three flats, B♭-E♭-A♭ → E♭ major). The flat rule works from two flats up; F major, with one flat, has to be memorized.
The solfège names used in Spanish-, French- and Italian-speaking countries (Do, Re, Mi, Fa, Sol, La, Si) correspond to C, D, E, F, G, A, B.