How ordinary a girl is Miley Cyrus? So ordinary that she has to sneak into her own concert. In the opening sequence of Hannah Montana: The Movie, Miley tricks her way into an arena, slips backstage, and puts on her blonde wig, makeup, and a spangly minidress to transform herself into that alterna-bubblegum rock chick and Pia Zadora look-alike, Hannah Montana. As her band pumps out those freeze-dried Avril Lavigne power chords, she exhorts the crowd with a lyric that could be her mantra: ''Everyone can rock out like a superstar!'' It's the halfway-sly conceit of Hannah Montana: The Movie that Miley, who talks about Hannah as if she were another person, has become addicted to her alter ego (with the accent on ego). She needs identity detox, which can only happen if she gets back to her simple country-girl roots by spending a few weeks in her small hometown of Crowley Meadow, Tenn.
Cyrus, as always, is a professional charmer (it's hard to resist when she leads a hip-hop hoedown), and the crusty folkiness of Billy Ray Cyrus as her real-life dad is as welcome as ever. But there's an awfully long stretch of country-living innocuousness before destiny beckons, and Miley has to become Hannah again so that she can lead a benefit concert to save the town from an evil developer. The surface lesson of the movie is that celebrity looks easy but is hard. The real lesson, as always, is that since even Miley has to work overtime to ''be'' Hannah, every girl in the audience if she tries hard enough can become the star she longs to be. B-