harmony vs harmonious

harmony is a noun but harmonious is not a noun.

Word	Noun	Adjective	Verb	Adverb
harmony	Yes	No	No	No
harmonious	No	Yes	No	No

harmony (noun)	harmonious (noun)
an agreeable sound property
compatibility in opinion and action
agreement of opinions
the structure of music with respect to the composition and progression of chords
a harmonious state of things in general and of their properties (as of colors and sounds); congruity of parts with one another and with the whole

harmony (adjective)	harmonious (adjective)
	musically pleasing
	exhibiting equivalence or correspondence among constituents of an entity or between different entities
	existing together in harmony
	suitable and fitting