Musical note standardised at 440 Hz, lying in the octave containing notes from C (middle C) to B. The lowest note on most pianos is A, the highest C. The MIDI system for electronic musical instruments and computers uses a straight count starting with note 0 for C at 8.1758 Hz up to note 127 for G at 12,544 Hz. A written note can also have a note value, a code that determines the note's relative duration. In order of halving duration, they are: double note (breve); whole note (semibreve); half note (minim); quarter note (crotchet); eighth note (quaver); sixteenth note (semiquaver).;
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