Sixty-fourth note going downward when the note is above or on the middle line of the staff. When the note head is below the middle line the stem is drawn to the right of the note head going upward. A single 64th note is always stemmed with flags, while two or more are usually beamed in groups . A similar, but rarely encountered symbol is the sixty-fourth rest (or hemidemisemiquaver rest, shown on the right of the image) which denotes silence for the same duration as a sixty-fourth note. Notes shorter than a sixty-fourth note are very rarely used, though the hundred
A♭ (musical note) A♭ (musical note) A (A-flat; also called la bémol) is the ninth semitone of the solfège. It lies a diatonic semitone above G and a chromatic semitone below A, thus being enharmonic to G, although in some musical tunings, A will have a different sounding pitch than G. When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the A above middle C (or A) is approximately 415.305 Hz. See pitch (music) for a discussion of historical variations in frequency. A/G is the only note to have only one other enharmonic.