- the set of syllables, do, re, mi, fa, sol, la, and ti, sung to the respective tones of the scale. All but do and ti are attributed to Guido d'Arezzo.
- the system of singing tones to these syllables.
- to use the sol-fa syllables in singing, or to sing these syllables.
- to sing to the sol-fa syllables, as a tune.
- short for tonic sol-fa
- to use tonic sol-fa syllables in singing (a tune)
