<P> Middle C ( the fourth C key from left on a standard 88 - key piano keyboard ) is designated C in scientific pitch notation , the most commonly recognized in auditory science , while both C and the Helmholtz designation c ' are used in musical studies . Other note - octave systems , including those used by some makers of digital music keyboards , may refer to Middle C differently . In MIDI , Middle C is note number 60 . </P>
which note is middle c on a piano
the fourth C key from left