John Travolta, who starred as 'Grease' bad boy heartthrob Danny Zuko, crashed the Hollywood Bowl's sing-along event Friday.

John Travolta pulled out the hair gel and leather to revive his role as Danny Zucco in a Hollywood Bowl screening of "Grease.

Fans at the 'Grease' Sing-A-Long screening at the Hollywood Bowl last night got a surprise when the original Danny Zuko ...

John Travolta made a surprise appearance at Friday night’s “Grease” sing-a-long at the Hollywood Bowl dressed as his iconic ...

John Travolta made a surprise appearance at Friday night’s “Grease” sing-a-long at the Hollywood Bowl dressed as his iconic ...

You never know what’s going to happen on those summer nights at the Hollywood Bowl. On Friday night, the iconic venue hosted ...

John Travolta, who starred as 'Grease' bad boy heartthrob Danny Zuko, crashed the Hollywood Bowl's sing-along event Friday. He surprised the audience and "Grease" co-stars alike.

The clip showed the “Pulp Fiction” alum walking out as the crowd went wild before Travolta joined his stunned “Grease” ...

John Travolta made a surprise appearance at Friday night’s “ Grease ” sing-a-long at the Hollywood Bowl dressed as his iconic drag racing, hip swinging 1950s bad boy Danny Zuko.

“Tonight at the Hollywood Bowl, for the first time I surprised everyone at the GREASE Sing-A-Long and dressed up as Danny Zuko. No one knew. Not even the cast,” Travolta revealed in his post.