Reading music · Key signatures
Key signatures
The sharps or flats at the start of every line tell you the key, and which notes to play black all the way through. Here are all fifteen, in treble and bass, with two tricks to name any of them in a second.
Sharp keys
Flat keys
What a key signature tells you
A key signature is a list of the notes that are always sharp or flat in the piece. A sharp on the top line of the treble staff means every F is played as F♯, in every octave, until the music says otherwise. It saves writing the same sharp hundreds of times, and it tells you the key at a glance.
The order of sharps
Sharps are always added in the same order: F♯ C♯ G♯ D♯ A♯ E♯ B♯. A key with three sharps has the first three: F♯, C♯, G♯. Remember it as Father Charles Goes Down And Ends Battle.
Each sharp is a fifth above the last.
The order of flats
Flats come in the reverse order: B♭ E♭ A♭ D♭ G♭ C♭ F♭. The first four spell BEAD; the whole line is Battle Ends And Down Goes Charles's Father.
Each flat is a fourth above the last.
Name the key in a second
- Sharps: go up a half step from the last sharp. In a key signature of F♯, C♯, G♯, D♯ the last is D♯; a half step up is E, so it's E major.
- Flats: the second-to-last flat is the key. B♭, E♭, A♭, D♭: the second-to-last is A♭, so it's A♭ major.
- Learn three by heart: no sharps or flats is C major, one sharp is G major, and one flat is F major.
- For the minor key, go down three half steps from the major key: D major's relative minor is B minor. Or find it on the circle of fifths, right inside the major key.
Major or minor?
Each key signature is shared by a major key and its relative minor: one sharp is G major or E minor. To tell which, look at the end of the piece: the last note in the bass, and the last chord, are almost always the home note. Minor pieces also often add a sharp or natural to the seventh note as they go (a D♯ in E minor), which a major piece wouldn't.
Key signature chart
| Key signature | Notes | Major key | Minor key |
|---|---|---|---|
| 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 |
Practise: name that key signature
Which major key has this key signature?
A few rounds a day and they'll become instant. The sharp keys usually come first; the flat keys take a little longer.
Reading it, but not sure you're playing it right? Ivory listens to you play and tells you what's off: a note that's missing, a hand that lands late, a sharp you forgot. Then it shows you how it should go.
Questions people ask
What is a key signature?
The sharps or flats written at the start of every line of music. They tell you which notes to play sharp or flat throughout the piece, and which key the music is in.
What is the order of sharps?
F♯, C♯, G♯, D♯, A♯, E♯, B♯: Father Charles Goes Down And Ends Battle.
What is the order of flats?
B♭, E♭, A♭, D♭, G♭, C♭, F♭: the order of sharps backwards. Battle Ends And Down Goes Charles's Father.
How do you tell the key from a key signature?
With sharps, go up a half step from the last sharp: the last sharp in D major is C♯, and a half step up is D. With flats, the second-to-last flat is the key: B♭, E♭, A♭ is E♭ major. One flat is F major, and no sharps or flats is C major.
How do you know if a key signature is major or minor?
Every key signature belongs to a major key and its relative minor. Look at the last note in the bass, and the first and last chords: if they're the minor key's note (A for a piece with no sharps or flats), it's minor. Minor pieces also often raise the seventh note, so a G♯ in a piece with no key signature hints at A minor.
How many key signatures are there?
Fifteen: C major with none, seven with sharps (G, D, A, E, B, F♯, C♯) and seven with flats (F, B♭, E♭, A♭, D♭, G♭, C♭). Three pairs are the same keys on the piano: B and C♭, F♯ and G♭, C♯ and D♭.