Tim Burton's Sweeney Todd is great. No two ways about it. It's great. If there is a problem though — aside from Johnny Depp's occasional David Bowie vocals — it is the lack of music. Burton's brilliant visuals come at a cost: the removal of the narrative chorus that drives Sondheim's original musical forward.
If you want to see the true power of the musical — probably the finest of the modern musicals, frankly — this DVD is a good place to start. It's a filmed-for-TV version of the stage show, starring the great George Hearn as the titular psychopathic barber and the quite brilliant Angela Lansbury as Mrs Lovett. Helena Bonham-Carter was a satisfactory pie maker but Lansbury, who created the role on Broadway, is astonishing. You'll never watch Murder She Wrote in the same way again.
It's not perfect. The technology of 1982 means that this isn't the greatest looking production and that the perverted excesses of the Beadle and Judge are very much downplayed, and Betsy Joslyn's Johanna is a little, shall we say, shrill. But ignore the flaws and savour instead Hearn and Lansbury and the intelligence, wit and sheer brilliance of Sondheim's score.