rhapsody vs epic

rhapsody and epic both are nouns.

Word	Noun	Adjective	Verb	Adverb
rhapsody	Yes	No	No	No
epic	Yes	Yes	No	No

As nouns, epic is a hypernym of rhapsody; that is, epic is a word with a broader meaning than rhapsody:

Other hypernyms of rhapsody include epic poem, epos, heroic poem.

rhapsody (noun)	epic (noun)
(in ancient Greece) an epic poem adapted for recitation	a long narrative poem telling of a hero's deeds
(music) a free instrumental composition in one extended movement; typically emotional or exuberant in character
an enthusiastic expression of emotion

rhapsody (adjective)	epic (adjective)
	constituting or having to do with or suggestive of a literary epic
	very imposing or impressive; surpassing the ordinary (especially in size or scale)