Who would have thought that the old formula about high school misfits who take on the established campus order and succeed had any life left in it? But Todd Graff shows that even the hoariest cliches can be made to work again, if they’re treated with affection and a dose of genuine feeling. “Bandslam” isn’t a great movie, and in the last act it loses its balance in going for the traditional big, heart-tugging ending. But until then it’s a kind of endearing throwback to pictures of a simpler time.

That’s not entirely surprising coming from Graff, whose genial 2003 “Camp” celebrated youngsters who aspired to parts on the Broadway boards. But it’s due not merely to him and co-writer Josh A. Cagan, but to the efforts of a talented cast.

The standout is Gaelen Connell, who plays retiring Will Burton, a kid tormented by classmates at his Ohio school and hoping things will change for the better when he and his protective mom (Lisa Kudrow) move to New Jersey. An avid fan of rock music both famous and obscure, he’s unexpectedly taken up as a friend by two girls. One’s Vanessa Hudgens’ edgy outsider Sa5m (“The 5 is silent,” she explains), and the other is Aly Michalka’s vivacious senior Charlotte, who was once the campus cheerleader princess but has abandoned that persona to help babysit young neighborhood kids and play in a garage band.

Charlotte’s group is in pretty bad shape, with no drummer and only two other players, including a nebbish named Bug (Charlie Saxton). But they’d like to challenge the school’s reigning group, a recent runner-up in the tri-state Bandslam contest, to which Charlotte’s old boyfriend Ben (Scott Porter) defected. Charlotte enlists Will, whose knowledge of all things rock is immediately apparent, to mold them into winners. And Will does, by adding intense drummer Basher (Ryan Donowho) as well as a cellist, some trumpeters and a keyboardist, changing the name to the hip I Can’t Go On I’ll Go On, and molding their sound meticulously. He also gets pointers from the more experienced Charlotte on how to overcome his shyness and romance standoffish Sa5m.

Of course, things can’t go smoothly in a movie like this. Ben ferrets out information on Will’s Ohio past that threatens to bring the maltreatment he got from kids back there eastward, and a change in Charlotte’s life breaks up the band. Will’s relationship with Sa5m hits a rocky patch, too. And even when things work out with the group and the kids are ready to do their thing at Bandslam, a last-act obstacle arises concerning the song they’re scheduled to perform—leading to an emotional crisis for Will that’s played out in a sequence more agonizingly stilted than affecting and a performance that, given its ad hoc character, is too flawless for words. Happily, Graff and Cagan at least come up with a twist that bows to new media in a fashion tween viewers will appreciate, and a cameo that’s as satisfying as the one by Stephen Sondheim was in “Camp.”

It would be hard to imagine “Bandslam” working at all if it weren’t for Connell, who plays Will with just the right mixture of vulnerability and bravado. Whether he can channel the charm into other roles remains to be seen, but right now he seems a major find—like a young Shia LaBeouf before he took the big blockbuster route. Hudgens nicely negotiates a part that’s like a reversal of the girly sweetness of “High School Musical,” and Michalka provides a nice contrast, though the explanation for Charlotte’s sudden change of character (and back again) is one anybody would have had trouble making convincing. Donowho and Saxton both get their share of laughs, and though Kudrow is more sedate than usual, she’s persuasive as a concerned mom (though a running gag involving her and Donowho falls flat). The picture was actually shot for the most part in Texas, but production designer Jeff Knipp and cinematographer Eric Steelberg manage to use the locations as good stand-ins for New Jersey and even, in one scene, a shuttered New York City club. The music will hardly blow anybody away, but it has the flavor of authentic pop.

Unlike the groups competing in the titular contest, “Bandslam” isn’t going to win any awards, but it’s a distinct step up from most striving-against-the-odds high school movies.