SALT LAKE CITY - Police in Utah say an officer who pulled over soul singer Gladys Knight was treated to an impromptu rendition of "Happy Birthday."

Pleasant Grove Police Capt. Mike Roberts says Knight was a passenger in the car stopped for speeding about 40 miles south of Salt Lake City on Wednesday night.

Officer Paul Rogerson was checking the driver's license when the woman said she was with Gladys Knight on the way to a Church of Jesus Christ of Latter-day Saints choir performance. Knight is a Mormon convert, and Rogerson says she was speaking at the event.

Rogerson told the woman it was his birthday and Knight also got out of the car and sung to him.

Police say Rogerson let the driver go with a warning.

A representative for Knight did not have immediate comment.