COMMA, originally, in Greek rhetoric, a short clause, some thing less than the "colon"; hence a mark (,), in punctuation, to show the smallest break in the construction of a sentence (Gr. KO/42a, something stumped or cut off, Ko7TECV to strike). The mark is also used to separate numerals, mathematical symbols, and the like. Inverted commas, or "quotation-marks," are placed at the beginning and end of a sentence or word quoted, or of a word used in a technical or conventional sense; single inverted commas are used for quotations within quotations.
In music, comma is the name for the extremely small and purely theoretical intervals of sound resulting from the slightly different vibration numbers which may be possessed by one and the same note, according to the different ways in vvhich it is arrived at by the process of tuning up or down from some other note.