blend in vs harmonize

blend in and harmonize both are verbs.

Word	Noun	Adjective	Verb	Adverb
blend in	No	No	Yes	No
harmonize	No	No	Yes	No

As verbs, harmonize is a hypernym of blend in; that is, harmonize is a word with a broader meaning than blend in:

Other hypernyms of blend in include accord, agree, concord, consort, fit in, harmonise.

blend in (verb)	harmonize (verb)
cause (something) to be mixed with (something else)	bring into consonance, harmony, or accord while making music or singing
blend or harmonize	bring into consonance or accord
	bring (several things) into consonance or relate harmoniously
	sing or play in harmony
	write a harmony for
	go together