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).;
Grace note notes is always noted in terms of exactly half of its principal note, but may be double or more. Where they are multiple, their proper notation must always equal exactly half of the principal note. (i.e. If the principal note is a quarter-note the grace note must be notated as an eighth- note, two sixteenth notes, four thirty-second notes, or eight sixty-fourth notes, if we are to set aside the concept of unnatural subdivisions of the beat such as the triplet, etc.) Grace notes, unlike what are referred to as cue-notes, never affect the rhythmic subdivision, or musical "count" of