harmonizing

verb (present participle)
UK /ˈhɑːmənaɪzɪŋ/
US /ˈhɑːrmənaɪzɪŋ/

Making different sounds or things fit together nicely.

The choir was harmonizing beautifully during the concert.


OTHER MEANINGS

2. Adding musical notes that sound pleasant with a main melody.

She spent the afternoon harmonizing the new song for the band.

3. Making different ideas, rules, or systems agree with each other.

The two countries are harmonizing their safety rules.

4. Bringing people together so they get along peacefully.

The teacher is harmonizing the opinions of the group.