Bill and Ted are back with a song to save the world.

Released 31 years after “Bill & Ted’s Excellent Adventure,” “Bill & Ted Face the Music” sees the return of Alex Winter and Keanu Reeves, as Bill and Ted, now middle-aged former rock musicians on a mission to finish a song in just 78 minutes. The co-stars joined senior lifestyle editor Marc Malkin on Variety and iHeart podcast “The Big Ticket” to discuss the long-awaited film.

The co-stars shared they hadn’t planned on a third film, until the writers came forward with new stories. “We never felt the world particularly needed a third, but when we were pitched this idea by [co-writers] Chris Matheson and Ed Solomon some years ago, we really did love the idea. It really made us laugh, and it warmed our hearts,” said Winter.

Winter also introduced “Face the Music” as the perfect family movie. Despite both actors portraying rockers, Winter explained Bill and Ted aren’t stoners but childlike adults. “It’s not like that was intentional, but I think that Keanu and I both always saw these kids as these characters, as having kind of a childlike view of the world or an innocent view, but not in a caricature-ish way, ideally,” he explained.

On the song that saves the world in the movie, Reeves shared the Beatles song “Ob-La-Di, Ob-La-Da” secretly helped the duo. Because they didn’t have the final song when filming, Reeves said, “For nights, we would just be listening and rock out to ‘Ob-La-Di, Ob-La-Da.’ It’s amazing how you can listen to that song a whole bunch and not get tired of it.”

Watch the full video interview above.