128th note
In music, a hundred twenty-eighth note or semihemidemisemiquaver or quasihemidemisemiquaver is a note played for 1⁄128 of the duration of a whole note. It lasts half as long as a sixty-fourth note. It has a total of five flags or beams. If human pitch perception begins at 20 Hz (1200/minute), then 128th notes become pitched at quarter note ≈ 160 bpm.
A single 128th note is always stemmed with flags, while two or more are usually beamed in groups. Notes this short are very rare in printed music, but not unknown. One reason that notes with many beams are rare is that, for instance, a thirty-second note at 
=50 lasts the same amount of time as a sixteenth note at =100; every note in a piece may be notated as twice as long but last the same amount of time if the tempo is also doubled. They are principally used for brief, rapid sections in slow movements. For example, they occur in the first movement of Beethoven's Pathétique Piano Sonata (Op. 13), to notate rapid scales. Another example is in Mozart's Variations on Je suis Lindor, where many of them are used in the slow twelfth variation.
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