- the act, process, or system of using certain syllables, especially the sol-fa syllables, to represent the tones of the scale.
- a system of naming the notes of a scale by syllables instead of letters derived from the 11th-century hexachord system of Guido d'Arezzo, which assigns the names ut (or do), re, mi, fa, sol, la, si (or ti) to the degrees of the major scale of C (fixed system) or (excluding the syllables ut and si) to the major scale in any key (movable system)