Tim McGraw joined Elton John, Kid Rock and the Doobie Brothers as one of the surprise performers in Milwaukee at a concert celebrating the 100th anniversary of Harley-Davidson motorcycles. More than 150,000 fans attended Sunday's (Aug. 31) concert hosted by actor and Harley-Davidson enthusiast Dan Aykroyd. McGraw and John teamed up to perform "Tiny Dancer." McGraw returns to Rayville, La., on Sept. 14 for his annual Swampstock celebrity softball game and concert. 09/02/03