What is the theme of hello, dolly?

Answer: A matchmaker named Dolly Levi takes a trip to Yonkers, New York to see the "well-known unmarried half-a-millionaire," Horace Vandergelder. While there, she convinces him, his two stock clerks and his niece and her beau to go to New York City. In New York, she fixes Vandergelder's clerks up with the woman Vandergelder had been courting, and her shop assistant (Dolly has designs of her own on Mr. Vandergelder, you see).

I don't know the answer to this but sounds like a interesting movie