An aspiring but untalented songwriter wannabe (Domhnall Gleeson) insinuates himself into an eccentric, punkish band fronted by the title character, a virtuoso/freak who never takes off his huge, papier-mâché stage head. Ever. Michael Fassbender, the actor inside the head, amazingly makes Frank a fully developed character without the use of his face. A talent that’s hard to hide. This affable oddity is funny, quirky, original and honest. It gradually deepens into an examination of the effects of social media hype on true creativity and of the thin line between genius and madness. Also Maggie Gyllenhaal. (95 min)