The range/compass of instruments on this site are presented in reference to that of the piano tuned to equal temperament (A-440 standard) and segmented into octaves articulated by the pitch class of 'C'. The lowest octave is given the designation C0 (C-zero), which has as its lowest sounding note C0 (frequency of approximately 16 cps) and includes all the chromatic pitches above it up to B0 (B-zero). Each successive octave span moving upwards is labelled with the next higher integer. ‘Middle C’ is therefore C4, ‘A-440’ is A4, the lowest pitch on the standard piano is A0, and the highest pitch on the piano is C8.
This system obviously serves best diatonic and chromatic instruments tuned to equal temperament and intended for use in the performance of any Western or Western-derived musical style. Instruments indigenous to many non-Western musical traditions are likely not intended to play in equal tempered tuning anchored to the A-440, or any other, pitch standard. Acknowledging the ethnocentric overtones of this choice of system for representing the pitch range of instruments, it is nonetheless expedient to incorporate it on this website in order to avoid lengthy digressions in the instrument entries about indigenous tuning and pitch naming practices. One small benefit of incorporating this system is that it allows the user to compare instrument ranges, at least generally, across cultural boundaries (e.g., the compasses of the Western concert flute, the Japanese shakuhachi, and the Javanese suling are all roughly the same, from around C4 to around C7).
Audio clips of the eighty-eight notes of the piano are found in the accordion table on this page. Each facet of this table contains the note names, frequencies in cycles-per-second (cps), and audio clips for the notes in one octave of the piano's total compass. Pitches in the lowest octave start not from C0, but from A0 (27.5 cps), which is the lowest sounding note on the standard piano. Only one pitch--C8--is found in the final facet of the table because that is the highest note on the piano. We thank Lawrence Fritts at the University of Iowa Electronic Music Studios for giving us permission to use these high fidelity audio samples, each of which we have edited down to a few seconds in duration (the full samples can be found on the UI Electronic Music Studios website). Pitch frequencies found in the table are derived from tone measurements presented in a manual titled Making Sense of Cents. We have rounded these measurements to the nearest tenth of a cycle. (by Roger Vetter)
Fritts, Lawrence. "Musical Instrument Samples: Piano." University of Iowa Electonic Music Studios website, accessed June 23 2015: http://theremin.music.uiowa.edu/MISpiano.html