We all have fond memories of Danny Zuko prancing around the hit 1978 film Grease. But now that 40 years have gone by, fans are dying to know: did John Travolta really sing in the movie?

The answer? Yes! John, now 64, sang alongside Olivia Newton-John and the rest of the cast in the iconic blockbuster. However, he wasn’t always supposed to sing “Greased Lightnin’.” According to a recent article written by Variety, John stole the part from one of his co-stars. The solo was supposed to go to Jeff Conaway (who played Kenickie), but it ultimately went to John. “I wanted the number,” John admitted. “And because I had clout, I could get the number.” Ouch!

During the film, John also sang songs including “Summer Nights,” “You’re the One That I Want,” “Sandy,” and “We Got Together,” which is interesting since his role almost went to Happy Days star Henry Winkler. We wonder if Henry would have sung as well as John did. In 2007, we got to see John sing again as Edna Turnblad in Hairspray.

We’re sure John would be open to a reunion since he made a reference to Grease at the 2017 Grammys while introducing country pair Keith Urban and Carrie Underwood. “Ladies and gentleman, the most dynamic duo since Sandy and Danny, Keith Urban and Carrie Underwood!” John said. Do you know what would have been better than that? If he and Olivia took the stage again! We can only hope…

Click through the gallery below to see the cast of Grease then and now!