Accidentals

Accidentals, in Music, are signs of chromatic alteration of the notes, differing from the Signature (q.v.) in applying only to particular notes, and not extending their effect beyond the bar in which they occur, or according to others, the first note of the next bar. They indicate a temporary change of key. They are five in number; the sharp (#), the double sharp (×), which raise the note to which they are prefixed a semitone and a tone respectively; the flat (♭) and the double flat (♭♭), which lower it correspondingly; and the natural (♮), which annuls the effect of preceding flats or sharps, whether accidental or in the signature.