com’ma

1. A breathing-mark. 2. A theoretical term indicating the minute difference between two tones nearly identical. (a) The comma syntonum, or c. of Didymus, is that between a major and a minor tone 80:81. (b) The comma ditonicum, or c. of Pythagoras, is that by which six whole notes with the ratio 9:8 exceed the octave, or 531 +: 524 +.