"Radio Rebel," With Debby Ryan on Disney Channel It's clear the indie kids will triumph in "Radio Rebel" from the first time you see Tara (Debby Ryan) in the hall of her high school, wearing a slouchy knit hat and flannel that scream "Seattle, 1991." Tara is an outsider, natch, but she also anonymously hosts an Internet radio show on which she shares her true feelings, groaning about the atomization of her peers into cruel cliques. In school every day, she's invisible. Online, she's a folk hero. "Radio Rebel," a film appearing on the Disney Channel on Friday night, is "Pump Up the Volume" for rugrats, a splash of anti-establishment insouciance between all of this network's shiny-cheeked go-getters and goofballs. It's also territory that the Nickelodeon offshoot the N got to several years ago with "Radio Free Roscoe." Ms. Ryan is a product of the Disney Channel farm system: she's had pickup work on "Wizards of Waverly Place" and "Hannah Montana"; a big role on "The Suite Life on Deck"; and now the lead on "Jessie," which had its premiere in the fall. She comes off like a less peppy version of Demi Lovato (who preceded her as the Disney Channel's would-be alt star). When she's in Radio Rebel mode, she's almost sultry, oozing confidence and disruptive flair. Even her meek school presence feels more John Hughes than Saturday morning television. Based on the novel "Shrinking Violet" by Danielle Joseph, this movie is a far less intense proposition than "High School Musical," "Camp Rock" or their offspring and, to be fair, at least in places, it is less reliant on caricature. Stacy (Merritt Patterson), the chief mean girl and Tara antagonist, turns out to have low self-esteem, and Tara's mother, who initially seems ill equipped to deal with a shy child, ends up unexpectedly reflective. Most of the rest of the characters are disposable, though: the caffeinated best friend, Audrey (Sarena Parmar), and even the supposed heartthrob Gavin (Adam DiMarco), who has huge features that do the work his words don't. The main flaw, though, is logistical: That hundreds of high school students would simultaneously tune in to an Internet radio show tests the bounds of credulity, as does the idea that a local radio station would hire an Internet cult figure and give over its evening airtime to her. I thought the Web liberated us from the tyranny of scheduled media, no? As Tara begins to embrace her power as Radio Rebel, things fall apart. The school's vindictive principal cancels the prom unless Tara comes forward, so she organizes an alternative dance, telling students, "Just come as you are." The only student who struggles with that is, of course, Tara herself. Radio Rebel was nominated for prom queen, and Tara shuns the spotlight. "What if I don't want to shine?" she gripes. What if shining isn't really my thing? Gavin had planned to take Stacy to boost his social status, but he naturally sees the error of his ways. When he bails, she melts down about the crowns they could have won, and he holds firm: "I don't want to be king. I never did. Tara outs herself at the prom, risking expulsion, but is saved by her peers, who one by one insist, "I'm Radio Rebel!" - a very "O Captain! My Captain!" moment. And Gavin, who earlier in the film was ditched by his smarmy, party-centric electro-rock band for being too sincere, steps onto the stage to play a meaningful guitar ballad called "Now I Can Be the Real Me." Radio Rebel Disney Channel, Friday night at 8, Eastern and Pacific times; 7, Central time. Produced by MarVista and Two 4 the Money Media. Directed by Peter Howitt; written by Erik Patterson and Jessica Scott, based on the novel "Shrinking Violet" by Danielle Joseph; Fernando Szew, Michael D. Jacobs, Robyn Snyder, Jane Goldenring, Kim Arnott and Oliver De Caigny, executive producers. WITH: Debby Ryan (Tara Adams), Sarena Parmar (Audrey), Adam DiMarco (Gavin), Merritt Patterson (Stacy) and Atticus Mitchell (Gabe).