monophonic vs music

monophonic is not a noun while music is a noun.

Word	Noun	Adjective	Verb	Adverb
monophonic	No	Yes	No	No
music	Yes	No	No	No

monophonic (noun)	music (noun)
	musical activity (singing or whistling etc.)
	punishment for one's actions
	any agreeable (pleasing and harmonious) sounds
	(music) the sounds produced by singers or musical instruments (or reproductions of such sounds)
	an artistic form of auditory communication incorporating instrumental or vocal tones in a structured and continuous manner

monophonic (adjective)	music (adjective)
consisting of a single melodic line
designating sound transmission or recording or reproduction over a single channel