noun, verb, -faed, -fa⋅ing.| 1. | Music. 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. |
| 2. | the system of singing tones to these syllables. |
| 3. | to use the sol-fa syllables in singing, or to sing these syllables. |
| 4. | to sing to the sol-fa syllables, as a tune. |