v go together
v write a harmony for
v sing or play in harmony
v bring (several things) into consonance or relate harmoniously
v bring into consonance or accord
v bring into consonance, harmony, or accord while making music or singing
v. （使）和谐( harmonize的第三人称单数 ); （使…与…）协调; （使）相称; 以和声唱歌或演奏