Sharp (music)

In music, sharp, dièse (from French), or diesis (from Greek) means higher in pitch. More specifically, in musical notation, sharp means "higher in pitch by a semitone (half step)" ,and has an associated sharp symbol, ♯, which may be found in key signatures or as an accidental. Sharp is contrasted with flat, which refers to a lowering of pitch. Intonation may be flat, sharp, or both, successively or simultaneously.

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.

In tuning, 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 said to be sharp with respect to the other. Furthermore, the verb sharpen means "raise the frequency of a note, typically by a small musical interval".

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