On Friday night, audiences turned up in their pink and leather jackets to rewatch 1978’s Grease. But imagine their surprise when John Travolta turned up as Danny Zuko to welcome the crowd?

John Travolta attended the Hollywood Bowl's Grease sing-along dressed as Danny Zuko to surprise fans, and stars like Hannah Waddingham were all about it.

John Travolta had a surprise in store for fans who attended a “Grease” sing-along at the Hollywood Bowl, showing up in full Danny Zuko regalia — an unexpected nod to his character in the classic ...