C flat major

C major is a major scale based on C, consisting of the pitches C, D, E, F, G, A, and B. Its key signature has seven flats — the enharmonically equivalent key signature B major (five sharps) is usually used instead. (see below: Scales and keys). C major is the only major or minor key, other than theoretical key, which has "flat" or "sharp" in its name, but whose tonic note is the enharmonic equivalent of a natural note (a white key on a keyboard instrument). Its relative minor is A-flat minor,... full article at wikipedia