reharmonisation vs reharmonization

reharmonisation and reharmonization both are nouns.

Word	Noun	Adjective	Verb	Adverb
reharmonisation	Yes	No	No	No
reharmonization	Yes	No	No	No

As nouns, reharmonisation and reharmonization are synonyms defined as:

reharmonisation and reharmonization: a piece of music whose original harmony has been revised

reharmonisation (noun)	reharmonization (noun)
a piece of music whose original harmony has been revised	a piece of music whose original harmony has been revised