Accidentals in Music

Symbols occurring outside the 10 signature, i.e. , in the course of a composition, and altering the pitch of the notes before which they are placed. They are the sharp (#), which raises such a note a semi-tone; the double sharp (×), which raises the note a whole tone; the flat (b), which depre es the note a semi-tone; the double-flat (bb), which depre es the note a whole tone; and the natural (И), () which cancels the changes effected by the other symbols. There is no uniformity in the use of accidentals in reference to the duration of their validity, though generally their effect is limited to the measures in which they occur.