The order of sharps and flats · Keys and key signatures · Music theory
Sharps are always written in the same order, fifth by fifth upward: F, C, G, D, A, E, B. Flats come in the reverse order, fifth by fifth downward: B, E, A,…
The order of sharps and flats
Sharps are always written in the same order, fifth by fifth upward: F, C, G, D, A, E, B. Flats come in the reverse order, fifth by fifth downward: B, E, A, D, G, C, F.
A key signature with three sharps is always the first three (F♯, C♯ and G♯); one with two flats, B♭ and E♭. Each accidental also has its fixed place on the staff.
You only need to learn one phrase. “F, C, G, D, A, E, B” reads one way for sharps and the other way for flats: the last accidental of one is the first of the other.
Where each accidental goes
The accidentals of a key signature do not go in just any octave: they follow a fixed pattern recognized at a glance. In treble clef the sharps form a zigzag starting on the top line (F) and the flats start on the third line (B). In bass clef the pattern is the same, two positions lower.
In tenor clef the sharp pattern changes, so as not to leave the staff. When copying a key signature, these positions matter: the same number of signs placed elsewhere is very hard to read.