"If you had told me that I'd make my Broadway musical comedy debut in front of my grandchildren, I would have said you're out of your mind," Billy Crystal told his opening night audience of "Mr. Saturday Night," after the cast made their curtain call bows at New York's Nederlander Theatre, last night.

The musical was adapted from Crystal's 1992 film of the same name.

It tells the story of comedy actor Buddy Young Jr. taking a shot at the biggest role of his career, while dealing with family issues, including his alienated brother and complicated relationship with his daughter.

Billy said, "This character has been in my soul since like, 1984" Crystal told the audience, outlining Buddy's evolution through TV specials and "SNL" appearances, before the movie.