John Travolta, who brought life to bad boy heartthrob Danny Zuko in the 1978 classic, crashed the Hollywood Bowl's sing-along event Friday. He surprised not just the audience, but also fellow "Grease" alumni as he sauntered on stage in his character's signature pompadour and leather jacket.

John Travolta's Danny Zuko reemerged at the Hollywood Bowl, 47 years after the star portrayed the Rydell High T-Bird in 'Grease' the movie.