Full disclosure in case the review sounds unduly. . . something: my first experience with Sweeney Todd occurred on 31 October, probably 1983, when I went with the person who was to become my wife to the Kennedy Center and saw the inimitable Angela Lansbury and (I think) Len Cariou perform. Angela Lansbury played Mrs. Lovett and you can catch bits of this performance on You Tube if you care to take a look. It is unmatchable in its sheer brilliance. Helena Bonham Carter had a hard act to follow, literally.
Tim Burton made some interesting choices in the film. The original Sondheim play was a dark comedy/satire/social commentary wrapped up in a rollicking, non-stop nearly grand guignol spectacle. Burton's choices are directed toward making a darker, more somber experience. Perhaps he was aiming for tragedy--unfortunately, the character of Sweeney hasn't the substance of a hero and so what we get is bathos--elegant and beautiful bathos, but bathos nevertheless. One doesn't come away with a sense of how tragic it all was or how, with a few minor choices things could have come out all right. One comes away with a sense of having visited some of the more secure precincts of bedlam where not a person seems to have any grasp of the real and rational.
I won't go into the story--suffice to say that it came out of the time of the penny dreadfuls, taking its place alongside such delights as Varney the Vampire and other such. Burton films it beautifully. Johnny Depp actually does a creditable job of singing his role. The same cannot be said of Helena Bonham Carter, unfortunately; however, her performance is not so terrible as to damage the structure or intent of the overall film.
One major problem I had with the film is that while the instrumental music suggesting "The Ballad of Sweeney Todd" is played frequently, the audience that has not seen the play will have no notion of where it comes from. This choice is one that comes from adapting a stage play to the screen, but it is also one that deprives the viewer of the frame of reference and the clear sense of where the play was meant to go. It is the primary blow that changes the film from dark comedy to bathos.
In all, while I liked the film greatly, I don't think the changes in tone served Burton or Sondheim well. We get a solid film with interesting if oddly disconnected performances, reminiscent of professional night in the psychiatric ward; however, iltle of the brilliance of the play shines through.
Despite that, I enjoyed, indeed liked the film a great deal. One must try to respect the intent and vision of the artist when viewing a work of art, and while I don't think this film is as strong as its Broadway source material, it still serves well.
One other point--we have a mini-Harry Potter reunion in the forms of Snape and Pettigrew who play two of the key conspirators in the downfall of Mr. Todd and family.
Recommended for adults--especially if you've seen the play. It provides an interesting contrast to the original.