Meaning of “harmonize” - Learner’s Dictionary

harmonize

verb [ I, T ] ( also UK -ise) uk us /ˈhɑːmənaɪz/
BE SUITABLE

to be suitable together, or to make different people, plans, situations, etc suitable for each other:

The gardens had been designed to harmonize with the natural landscape.
MUSIC

to sing or play music in harmony

(Definition of “harmonize” from the Cambridge Learner’s Dictionary © Cambridge University Press)