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
Pulses per quarter note Pulses per quarter note PPQN (Pulses Per Quarter Note, also known as PPQ, Pulses Per Quarter and TPQN, Ticks Per Quarter Note) is the smallest unit of time used for sequencing note and automation events, both by step sequencers and in the MIDI standard. Most MIDI sequencers allow the number of PPQ to be varied for more or less temporal resolution depending on the needs of the performer. If there are too few PPQ any performance recorded into the MIDI sequencer may sound artificial (being quantised by the Pulse rate) or lose subtle variations in timing that gives music a