c

  1. The keynote of the normal or "natural" scale, which has neither flats nor sharps in its signature; also, the third note of the relative minor scale of the same.
  2. C after the clef is the mark of common time, in which each measure is a semibreve (four fourths or crotchets); for alla breve time it is written /.
  3. The "C clef," a modification of the letter C, placed on any line of the staff, shows that line to be middle C.
  4. As a numeral, C stands for Latin centum or 100, CC for 200, etc.