solmization vs singing

solmization and singing both are nouns.

Word	Noun	Adjective	Verb	Adverb
solmization	Yes	No	No	No
singing	Yes	Yes	No	No

As nouns, singing is a hypernym of solmization; that is, singing is a word with a broader meaning than solmization:

solmization: singing using solfa syllables to denote the notes of the scale of C major
singing: the act of singing vocal music

Other hypernyms of solmization include vocalizing.

solmization (noun)	singing (noun)
singing using solfa syllables to denote the notes of the scale of C major	the act of singing vocal music
a system of naming the notes of a musical scale by syllables instead of letters	disclosing information or giving evidence about another

solmization (adjective)	singing (adjective)
	smooth and flowing