harmonise vs blend

harmonise is not a noun while blend is a noun.

Word	Noun	Adjective	Verb	Adverb
harmonise	No	No	Yes	No
blend	Yes	No	Yes	No

As verbs, blend is a hyponym of harmonise; that is, blend is a word with a more specific, narrower meaning than harmonise:

Other hyponyms of harmonise include coordinate, blend in, go.

harmonise (noun)	blend (noun)
	the act of blending components together thoroughly
	a new word formed by joining two others and combining their meanings
	an occurrence of thorough mixing

harmonise (verb)	blend (verb)
bring into consonance, harmony, or accord while making music or singing	mix together different elements
bring into consonance or accord	combine into one
bring (several things) into consonance or relate harmoniously	blend or harmonize
sing or play in harmony
write a harmony for
go together