화성으로 노래하다

harmonise(verb)

to sing or play musical instruments in harmony.

(단음의 멜로디 등에) 화음을 붙이다

harmonise(verb)

to add different parts to (a melody) to form harmonies.

조화시키다

harmonise(verb)

to (cause to) be in harmony or agreement

The colours in this room harmonize nicely.