tonic sol-fa 
noun [mass noun]
A system of naming the notes of the scale (usually doh, ray, me, fah, soh, lah, te) used especially to teach singing, with doh as the keynote of all major keys and lah as the keynote of all minor keys. See solmization.He took lessons in piano and harmony from the local organist, bought a cello and started to learn it, and at the age of sixteen made his first attempts at composition, initially in tonic sol-fa....
- The tonic sol-fa method for sight-singing was much used in schools and by choirs, especially Welsh male-voice choirs.
- Some hymn books had staff notation and words, some were words only and some were words and tonic sol-fa.