musical theme vs melodic theme

musical theme and melodic theme both are nouns.

Word	Noun	Adjective	Verb	Adverb
musical theme	Yes	No	No	No
melodic theme	Yes	No	No	No

As nouns, musical theme and melodic theme are synonyms defined as:

musical theme and melodic theme: (music) melodic subject of a musical composition

Other synonyms of musical theme include idea, theme.

musical theme (noun)	melodic theme (noun)
(music) melodic subject of a musical composition	(music) melodic subject of a musical composition