In making the leap from movie mogul to lead theater producer with his musical, “Finding Neverland,” Harvey Weinstein has fired or lost more actors, artists and executives than most impresarios do on their shows. He has overseen spending of roughly $20 million (before tax writeoffs) on a world premiere run in Britain and then on an entirely new version of the musical, which opens April 15 on Broadway. He has thrown himself into the role of script doctor, huddling over a laptop the other week with the show’s book writer, James Graham, trying to punch up jokes. He has even fussed over the dog in the cast, pushing for a real-live version instead of an actor.

Yet Mr. Weinstein has been more than a hands-on producer. At 63, he has also become a student again, learning the art and craft of making musicals, one of the trickiest entertainment forms to get right.

The experience has been both searing and enlightening for him, as he’s gone from rough relationships with his first creative team to a close collaboration with his current one, led by the Tony Award-winning director Diane Paulus. Ask Mr. Weinstein what didn’t work when he started developing the musical, and he is willing to look in the mirror.

“I don’t think I worked,” Mr. Weinstein said, in a recent interview, about his feel for theater early on in the show’s history. “I think it was me, more than anything else. If I knew what I know now, four and half years later, we could have done better.”