Ever since Jodie Foster and Kurt Russell hit adolescence onscreen, the suits at Walt Disney have known what teen spirit smells like: money. These days, the target demographic is pervasively middle-schoolish and younger. For the past decade, the so-called “tween” market — mostly girls roughly between the ages of 8 and 12 — has propelled the careers of one superstar after another, even as its core members have passed into their college years and been replaced by a new generation of turbo-lunged squealers.

These manic mallrats get their due in a new 3-D spectacle that centers around and celebrates the new Queen of Tween. “Hannah Montana and Miley Cyrus: Best of Both Worlds,” a live concert film that opens today, finds them screaming at jet-engine volume in a high-pitched montage that was captured at various arenas playing host to Ms. Cyrus’s national tour of the same name. But the high-definition video, which is getting a one-week theatrical run (complete with 3-D glasses) before distribution in other formats, isn’t only a tribute to the respiratory health of young America. It’s a monument to its buying power, and the rather stunning process by which prefab phenomena are created.

Ms. Cyrus, a 15-year-old pop starlet, sold out tickets for her 2007 tour in a blink of an eye, outgrossing such veterans of the Enormo Dome circuit as the Police and Bruce Springsteen. On her outrageously successful Disney cable series, the actress and singer plays a high-school student named, uh, Miley (on the show, she’s Miley Stewart), who hides a secret identity: that of Hannah Montana, a sassy, blond-wigged teen pop sensation. The story lines juggle corny banter and parental homilies (the long-discarded country star Billy Ray Cyrus, of “Achy Breaky Heart” fame, duplicates his real-life role as Miley’s shaggy-headed, warm-hearted father), and use Ms. Cyrus’s dual identity as a source of endless plot contrivances. Lest anyone snicker, the show has industry credit. It won an Emmy for its inaugural 2006 season, and has attracted guest performers such as Larry David and Dolly Parton.

Thanks to the Disney show, two albums, two tours, movies, and merchandising, Ms. Cyrus earned $3.5 million last year, ranking 17th on Forbes’s list of highest earners under the age of 25. And yet, as the frequent, gliding shots of all those eager faces in her audience make clear, Ms. Cyrus’s musical appeal is still sealed inside the magical hermetic envelope of Tweendom. If there’s nothing in this 75-minute sprint through 22 tunes that would likely be played at a strip club — no “I’m a Slave for You” (Britney) or “Dirrty” (Christina) — neither is there any songwriting that transcends its own formula for unexpected classicism, as did the Backstreet Boys’ “I Want It That Way.”

Of course, that stuff would sound Jurassic to the kids cheering on Ms. Cyrus through her spirited assertions of adolescent imperative. But a lot of the material, which shifts slightly in tone and intent as the performer doffs her glitzy Hannah Montana outfits for the spunkier attire of Miley Cyrus, draws on older sources — even older than “Achy, Breaky Heart.”

Ms. Cyrus, who belts lyrics in a strong, girlish voice that is bland but not unlikable, comes across like the love child of Garth Brooks and the Bangles. It’s 1980s Los Angeles frisky-girl power pop, sanitized of its racier insinuations (well, virtually any insinuations at all), and jacked up on Garthian arena crunch.

Ms. Cyrus even emerges from beneath the stage, exiting a hydraulic riser like Mr. Brooks did in the 1990s. To satisfy fleeting attention spans, there is also a lot of hyperkinetic choreography by Kenny Ortega, who designed the production and throws in nods to Madonna and Cyndi Lauper. Strangely, none of the backup dancers look to be even close to Ms. Cyrus’s age. They look like young suburban soccer moms enjoying a really hip aerobics class.

The film, directed by Bruce Hendriks (whose only directorial credit is ESPN’s “Ultimate X: The Movie”), is slickly constructed, offering just enough behind-the-scenes details to invite a sense of familiarity with Ms. Cyrus, whose attitude is cheerful-jocular, and rather refreshingly chaste even when she’s rocking cheerleader socks. While Ms. Spears — tween diva of a decade gone — plays psycho to her paparazzi, and her underage sister, Nickelodeon star Jamie Lynn Spears, stares down the miracle of childbirth, there’s a sense of relief in watching Ms. Cyrus. She’s still hovering in a bubble, one that may or may not carry her toward a richer artistry, but which has mostly kept her clear of the darkest recesses of TMZ.com. Here’s hoping, by the time it bursts, she’ll be ready to flip Hannah Montana’s wig and make her own name as immediately memorable.