Sharp (music)

In music, sharp, dièse (from French), or diesis (from Greek)[lower-alpha 1] means, "higher in pitch". More specifically, in musical notation, sharp means "higher in pitch by one semitone (half step)". Sharp is the opposite of flat, which is a lowering of pitch.

A sharp symbol, , is used in key signatures or as an accidental. For instance, the music below has a key signature with three sharps (indicating either A major or F minor, the relative minor) and the note, A, has a sharp accidental.

Under twelve-tone equal temperament, B, for instance, sounds the same as, or is enharmonically equivalent to, C natural (C), and E is enharmonically equivalent to F. In other tuning systems, such enharmonic equivalences in general do not exist. To allow extended just intonation, composer Ben Johnston uses a sharp to indicate a note is raised 70.6 cents (ratio 25:24), or a flat to indicate a note is lowered 70.6 cents.[1]

In intonation, sharp can also mean "slightly higher in pitch" (by some unspecified amount). If two simultaneous notes are slightly out-of-tune, the higher-pitched one (assuming the lower one is properly pitched) is "sharp" with respect to the other. Furthermore, the verb sharpen means to raise the pitch of a note, typically by a small musical interval.