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 one semitone (half step)". Sharp is the opposite of flat, which is a lowering of pitch.
There is an associated sharp symbol which resembles "#", ♯, which may be found 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.
Moreover, under twelve-tone equal temperament, B♯, for instance, sounds...