Sir Paul McCartney got his birthday weekend off to a cheerful start in Las Vegas, Nevada on Thursday night (15JUN06) by checking out Cirque Du Soleil's new Beatles tribute LOVE. The rocker, who turns 64 tomorrow (18JUN06), joined show co-producer SIR George Martin and friends at the Mirage for the high-flying spectacle. And the former BEATLE was in for a treat when he paid a visit to the cast and crew backstage after the show - they sang a rendition of HAPPY BIRTHDAY to him. Sunday's birthday is a landmark one for the troubled star - he wrote WHEN I'M 64 when he was a teenager. It was reportedly the second song her ever wrote.