<P> This table shows that each scale starting on the fifth scale degree of the previous scale has one new sharp, added in the order given above . </P> <P> "Flat key signatures" consist of one to seven flats, applied as: BEADGCF The mnemonic device is then reversed for use in the flat keys: "Battle Ends And Down Goes Charles' Father". The major scale with one flat is F major . In all other "flat major scales", the tonic or key note of a piece in a major key is four notes below the last flat, which is the same as the second - to - last flat in the signature . In the major key with four flats (B ♭ E ♭ A ♭ D ♭), for example, the penultimate flat is A ♭, indicating a key of A ♭ major . </P> <Table> <Tr> <Th> Major key </Th> <Th> Number of flats </Th> <Th> Flat notes </Th> <Th> Minor key </Th> <Th> Enharmonic equivalent </Th> </Tr> <Tr> <Td> C major </Td> <Td> 0 </Td> <Td> </Td> <Td> A minor </Td> <Td> None </Td> </Tr> <Tr> <Td> F major </Td> <Td> </Td> <Td> B ♭ </Td> <Td> D minor </Td> <Td> None </Td> </Tr> <Tr> <Td> B ♭ major </Td> <Td> </Td> <Td> B ♭, E ♭ </Td> <Td> G minor </Td> <Td> None </Td> </Tr> <Tr> <Td> E ♭ major </Td> <Td> </Td> <Td> B ♭, E ♭, A ♭ </Td> <Td> C minor </Td> <Td> None </Td> </Tr> <Tr> <Td> A ♭ major </Td> <Td> </Td> <Td> B ♭, E ♭, A ♭, D ♭ </Td> <Td> F minor </Td> <Td> None </Td> </Tr> <Tr> <Td> D ♭ major </Td> <Td> 5 </Td> <Td> B ♭, E ♭, A ♭, D ♭, G ♭ </Td> <Td> B ♭ minor </Td> <Td> C ♯ major / A ♯ minor </Td> </Tr> <Tr> <Td> G ♭ major </Td> <Td> 6 </Td> <Td> B ♭, E ♭, A ♭, D ♭, G ♭, C ♭ </Td> <Td> E ♭ minor </Td> <Td> F ♯ major / D ♯ minor </Td> </Tr> <Tr> <Td> C ♭ major </Td> <Td> 7 </Td> <Td> B ♭, E ♭, A ♭, D ♭, G ♭, C ♭, F ♭ </Td> <Td> A ♭ minor </Td> <Td> B major / G ♯ minor </Td> </Tr> </Table> <Tr> <Th> Major key </Th> <Th> Number of flats </Th> <Th> Flat notes </Th> <Th> Minor key </Th> <Th> Enharmonic equivalent </Th> </Tr>

What is one flat in the key signature