That's just the life School of Rock's Dewey Finn leads, and just barely. Dewey, played by Black, is still chasing Barry's dream: He's the stage-diving, solo-taking guitarist in a hair-metal band that thinks Dewey an embarrassment, a no-talent who'll keep the band from winning a local battle of the bands -- a real punch in Dewey's ample gut, considering the band resembles a third-rate Poison tribute act. Disgraced, he takes to sleeping all day on the couch of pal Ned (Mike White, who also wrote the screenplay) and Ned's girlfriend, Patty (Sarah Silverman), who demand he get up, get a job or get moving. Dewey tells Ned he'll just temp like he does; Ned, a substitute teacher, says Dewey "wouldn't last a day." Ms. Foreshadowing, meet Mr. Plot Point.
Dewey, assuming Ned's identity, ends up teaching at a hoity-toity private school run by the uptight Principal Mullins (Joan Cusack, not nearly the sympathetic boss her brother was). At first he brushes off the kids; Dewey's idea of learnin' is telling the kids, a precocious multiethnic lot, they're doomed to be failures. Then he overhears them jamming in music class and figures he can prod the prodigies into joining his group for the battle of the bands, which involves deceiving the principal and taking the kids out of school without permission -- very sketchy stuff, all made to look endearing. From there School of Rock turns into Mr. Holland's Opus with an AC/DC-Led Zep soundtrack, Dead Rocker's Society, The Emperor's Club (if by "Emperor" you mean the Norwegian Viking-metal band of the late '90s). Carpe diem in this case translates into, "Rock on, little dudes."
After his turgid think pieces Waking Life and Tape, Linklater seems delighted to romp in the mainstream again with a rock soundtrack turned up to eleven. The Austin-based filmmaker, shooting entirely in Manhattan, hasn't made something so enjoyable since Dazed and Confused, a bong-hit of a movie that managed to be nostalgic without inhaling noxious wistful fumes. School of Rock, populated by bright-shiny faces given a Revenge of the Nerds happy ending, is light and meaningless but never worthless. It merely aspires to be a good time and is just that and nothing more, a grin-worthy buzz that wears off in the parking lot.
Chuck & Buck and The Good Girl writer White, who likes revealing the hidden kinks and naughty secrets behind the mundane façade of the everyday, isn't interested this time in the dark side; he too is all light and happiness. Otherwise he would have ended School of Rock with Dewey in the back of a police car headed for a long stint in the slammer, after he's found out by outraged parents aghast at his revelation that he has "touched your kids." (In the good way, of course.) Instead we're given hugs and kisses all around, none of them creepy even though the teacher was just an impostor looking for a paycheck.
Of course, the movie would be less than nothing without Black, finally allowed to charge ahead without a director acting like his movie set's a china shop. School of Rock would be saccharine without him, feel-good that tastes awful. Black, the tenacious B in folk-metal-art-rock cut-ups Tenacious D, plays himself, or certainly to the expectations of those enamored of his convulsive outbursts and eyebrow spasms. His is a curriculum of metal moves and guitar-hero histrionics taught to kids who were hired because they could actually play. Dewey's the sub you pray for but are scared of when he actually shows up, with his eyes wild and mouth screwed into an ex-con's grin. Without Black, School of Rock wouldn't pass.