harmonize

• Well, we all know Diana couldn't harmonize -- but you get the point! —  CLAY CANE // GET YOUR LIFE
• Valley natives Shanti Gruber and Megan Goodwin will play acoustic guitar and harmonize, according to Standiford. —  Aspen Times - Top Stories
• These we shall attempt to harmonize, and if we succeed, it will only be by mutual concessions and compromises. —  A Report of the Debates and Proceedings in the Secret Sessions of the Conference Convention For Proposing Amendments to the Constitution of the United States, Held at Washington, D.C., in February, A.D. 1861
• It can harmonize, assimilate, and protect the several parts and members, and extend the benefit of its foresight and precautions to each. —  The Federalist Papers
• They harmonize, my friend--they concatenate Mr. Fenton," proceeded Gillespie, "you are a young gentleman Yes, sir, that's the term. —  The Black Baronet; or, The Chronicles Of Ballytrain The Works of William Carleton, Volume One

Roget's II: The New Thesaurus

Allen's Synonyms and Antonyms