Fundamentals
Key Signatures and the Order of Sharps and Flats
Sharps arrive in the order F C G D A E B and flats in reverse. The order is the circle of fifths written out, one signature at a time.
Flat (♭)
An accidental that lowers a note by one semitone, written as ♭ before the note head.
Also called: flat sign
A flat (♭) lowers the pitch of a note by one semitone. On the keyboard the flat of a note is the key immediately below it, so B♭ is the black key just below B, and E♭ is the black key just below E. A flat in the key signature applies to every instance of that letter in the piece, while a flat written before a note applies to that note for the rest of the measure. Flats are added in the order B, E, A, D, G, C, F. F major has one flat, B♭, and B♭ major has two, B♭ and E♭. Each added flat moves the tonic a perfect fourth up, from F to B♭ to E♭.
Related terms
- Sharp (♯)An accidental that raises a note by one semitone, written as ♯ before the note head.
- AccidentalA sign before a note that raises or lowers its pitch by a semitone, or cancels an earlier sign, relative to the key signature.
- Key signatureThe sharps or flats written after the clef that set which notes are altered throughout a piece unless cancelled.
- EnharmonicDescribes two notes or intervals that sound the same but are written differently, such as C♯ and D♭.