Key signatures
The key signature is the set of sharps or flats written right after the clef: they apply to the whole piece and tell you the key. The order of sharps is always F, C, G, D, A, E, and B; the order of flats is the same backwards: B, E, A, D, G, C, and F. With sharps, the major key is a half step above the last sharp; with flats, it is the second-to-last flat.
Practice: which key is this signature?
A key signature appears, in treble or bass clef: pick the key. Each round has 10 questions.
Round over
| Key signature | Accidentals | Major key and relative minor |
|---|---|---|
| no sharps or flats | 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 sharp minor | |
| 4 sharps (F♯, C♯, G♯, D♯) | E major C sharp minor | |
| 5 sharps (F♯, C♯, G♯, D♯, A♯) | B major G sharp minor | |
| 6 sharps (F♯, C♯, G♯, D♯, A♯, E♯) | F sharp major D sharp minor | |
| 7 sharps (F♯, C♯, G♯, D♯, A♯, E♯, B♯) | C sharp major chords in D flat major, the same sound A sharp minor chords in B flat minor, the same sound | |
| 1 flat (B♭) | F major D minor | |
| 2 flats (B♭, E♭) | B flat major G minor | |
| 3 flats (B♭, E♭, A♭) | E flat major C minor | |
| 4 flats (B♭, E♭, A♭, D♭) | A flat major F minor | |
| 5 flats (B♭, E♭, A♭, D♭, G♭) | D flat major B flat minor | |
| 6 flats (B♭, E♭, A♭, D♭, G♭, C♭) | G flat major chords in F sharp major, the same sound E flat minor chords in D sharp minor, the same sound | |
| 7 flats (B♭, E♭, A♭, D♭, G♭, C♭, F♭) | C flat major chords in B major, the same sound A flat minor chords in G sharp minor, the same sound |
The trick to find the key
- Sharps: look at the last sharp and go up a half step. Last sharp G♯ → A major.
- Flats: the major key is the second-to-last flat. Flats B♭, E♭, A♭ → E♭ major. A single flat (B♭) is F major: just memorize that one.
- No sharps or flats: C major or A minor.
- The relative minor (same key signature) is 3 half steps below the major, on the 6th degree: C major → A minor; G major → E minor.
- Order of sharps: F, C, G, D, A, E, and B (Father Charles Goes Down And Ends Battle). Flats are the same order backwards (Battle Ends And Down Goes Charles’ Father).
Circle of fifths
Each fifth up adds a sharp; each fifth down adds a flat. The circle of fifths shows the 12 keys in that order, with the relative minors inside.
See also
Frequently asked questions
What is the order of sharps?
F, C, G, D, A, E, and B (Father Charles Goes Down And Ends Battle). Each sharp key signature uses the first ones on that list: 3 sharps = F♯, C♯, G♯.
What is the order of flats?
B, E, A, D, G, C, and F: the order of sharps backwards. 2 flats = B♭, E♭.
How do you find the key from the key signature?
With sharps, go up a half step from the last sharp. With flats, the key is the second-to-last flat (and a single flat is F major). The relative minor is 3 half steps below the major.
Why are there 15 key signatures if there are 12 keys?
Three keys have two spellings with the same sound: B major = C flat major, F sharp major = G flat major, and C sharp major = D flat major. Each spelling has its own key signature, from 7 flats to 7 sharps.
Does the key signature apply to every octave?
Yes. A sharp on F in the key signature applies to every F in the piece, at any height, until a natural sign appears (which lasts only until the end of that bar) or a new key signature.