After a dreary succession of virtually identical big-ballad albums, Celine Dion has, thank God, finally tried something a bit different. In fact, in a career move that's suspiciously reminiscent of Cher, she's gone disco - augmenting her vocal histrionics with guitars, echoey beats and dramatic electronic effects. Maybe it's got something to do with her new gig as the resident act at a Las Vegas casino - after all, if you're performing in front of a crowd of drunken gamblers, you need something lively to hold their attention. The problem is, Dion's songwriters seem to have been under strict instructions to keep the material as bland as possible. And while her glass-shattering voice is as spectacular as ever, she still doesn't sound as if she believes a word of what she's singing. One Heart is certainly one of her better collections - but frankly, that isn't saying very much.