EW has an exclusive look at the iconic "Johnny B. Goode" number from Back to the Future: The Musical. Casey Likes, who plays Marty McFly, had to perfect his guitar skills to perform the number live. Likes stars alongside Roger Bart and Hugh Coles as Doc Brown and George McFly, reprising their roles from the West End production. The musical, opening on Broadway, features songs from the original film and a score by Alan Silvestri. Likes tries to make the role his own while channeling the feelings Michael J. Fox brought to the character.