Bruce Springsteen surprises audience at Billy Joel concert

Bruce Springsteen propped himself on top of Billy Joel's piano to sing a duet with The Piano Man, who was celebrating his 100th concert at Madison Square Garden on Wednesday night.Joel told the energetic crowd he had a guest coming onstage who has won a Grammy, Oscar and Tony. Springsteen emerged, surprising the feverish and fanatic audience, who loudly cheered "BRUCE.""Congratulations Billy on your 100th show," Springsteen yelled."Ready, Billy?" he asked, as Joel began to play while sitting at