Key signatures: flats and the circle of fifths

Learn the flat keys F, B♭ and E♭ and see every key on the circle of fifths.

Flat keys

Build a major scale on F: F, a tone to G, a tone to A, a semitone to... a semitone above A is B♭. So F major has one flat in its key signature.

Flats also come in a fixed order, the reverse of the sharps: B, E, A, D, G, C, F.

F major: one flat, B♭

B♭ major: B♭ and E♭

E♭ major: B♭, E♭ and A♭

How to tell the key from the flats. The tonic is the second-to-last flat in the key signature. Flats B♭, E♭: tonic B♭. Flats B♭, E♭, A♭: tonic E♭. F major has only one flat and no second-to-last, so learn it by heart.

Practice: One flat

Practice: The second-to-last flat

Practice: Melodic dictation in F major

The circle of fifths

Going up from C by fifths, each new key has one more sharp: C (0), G (1), D (2), A (3), E (4), B (5), F♯ (6). Going down by fifths, each key gains a flat: C (0), F (1), B♭ (2), E♭ (3), A♭ (4), D♭ (5), G♭ (6).

The two branches meet at the bottom: F♯ major and G♭ major sound the same, one key written two ways. The result is a closed circle of twelve keys: the circle of fifths.

Neighbours on the circle differ by one sign and sound related. That is why music most often moves to a neighbouring key on the circle.

Practice: A neighbour on the circle

Practice: Which key?