Here's a musical I've never seen on a stage: George M, the story of George M. Cohan, told (reportedly) a bit more accurately than the movie Yankee Doodle Dandy and featuring songs written by the man himself. It opened in New York in April of 1968 to mixed reviews, ran almost exactly one year (433 performances) and won a Tony nomination for its star, Joel Grey.
In 1970, it was adapted for a star-filled television special with Grey repeating the title role and Bernadette Peters (who played Cohan's sister on Broadway) with Nanette Fabray, Jack Cassidy, Blythe Danner, Lewis J. Stadlen, Anita Gillette, Jesse White and Red Buttons. This version, unlike what played at the Palace Theater in New York, opens with those actors playing themselves preparing to do a run-through of the play. At least, I don't think the Broadway version was framed that way. This is that TV version and you may enjoy it, especially if you like seeing Jack Cassidy steal every scene he's in…