The latest Broadway show to hit the silver screen is an eclectic celebration of all things 80s, unless those things include drugs or AIDS or, you know, anything of genuine interest or significance bar Tom Cruise in leather chaps. Boasting a ruthlessly PG-ified script, a series of songs you’ll probably never have heard before and Bryan Cranston getting gently spanked, Rock of Ages is just silly enough to take the edge off how dull it is.