No matter how divided audiences are on the new musical "Sweeney Todd"—and they are likely to be sharply divided—few will be able to deny its enormous impact. It comes across as forcefully as any musical in recent memory.

The division will be largely over the musical's subject matter….

"Sweeney Todd" incorporates all the contrasting cliches of 19th Century melodrama: the corrupt rich (the judge) versus the downtrodden; the evil versus the innocent (Sweeney's daughter Johanna, in a straw bonnet and long blond curls, is the essence of Victorian purity); a sordid daily existence versus dreams of escape. Two of the most effective, as well as most melodic, songs in "Sweeney Todd" deal with fantasies of a better life. In one, Mrs. Lovett describes to Sweeney what a beautiful life they could lead at a resort "By the Sea." In another, a young assistant to Mrs. Lovett...