This photo provided by officer Paul Rogerson of the shows Rogerson, right, of the Pleasant Grove Police Department in Utah, singer Gladys Knight, center, and Rogerson's wife, left. Knight was a passenger in the car stopped for speeding in the town about 40 miles south of Salt Lake City, Pleasant Grove Police Capt. Mike Roberts said. Officer Rogerson got the driver's license and was checking it in his patrol car when the woman told him that she was with Knight on the way to a Church of Jesus Christ of Latter-day Saints choir event. (Courtesy of Paul Rogerson via AP)SALT LAKE CITY (AP) — A Utah police officer who pulled over a car carrying iconic soul singer Gladys Knight was treated to an impromptu rendition of "Happy Birthday."