Tim Burton’s Sweeney Todd (A-) is a monster musical. Johnny Depp and Helena Bonham Carter, neither renowned for their singing voices, sink their teeth into Sondheim’s gruesome tale of a demon barber bent on revenge against humanity that wronged him and his skirted accomplice who makes meat pies out of the corpses from his haircuttery. Atmospheric London sets, lovely tunes and absolutely blood-spewed sequences don’t often go together seamlessly, but Burton orchestrates them quite nicely here, thank you very much. It’s one of the director’s best works in years.