Ziegler’s performance as Music, however, is the standout disaster, serving us “Autism” the Rain Man way, all tics and whooping and capital ‘A’ Acting. She affects a honking, hiccuping gait occasionally punctuated by phrases – “make your eggs”, “braid your hair” – delivered in a voice that lands somewhere between a school bully mimicking Meryl Streep’s low register and a dog waking up from dental surgery.