As the lights in the auditorium go down for the start of School of Rock, The Musical, there’s an announcement that the children in the cast really do play their own instruments – and when you see how rocking awesome they all are, you can understand why some audience members have assumed that they must be pretending. These kids really do climb to the top of Mount Rock.

Brent Hill and cast. Photograph © Matthew Murphy

School of Rock is based on the 2003 Richard Linklater film starring Jack Black. Andrew Lloyd Webber saw its potential for the stage and snapped up the rights, writing the score with lyrics by Glenn Slater and book by Julian Fellowes (Downton Abbey).

The musical sticks fairly closely to the film, telling the story of slobby no-hoper Dewey Finn, a rock ‘n’ roll nerd who desperately wants to win Battle of the Bands. But a few weeks away from the competition, things start to go downhill fast. He is dumped from the band No Vacancy for constantly upstaging the lead singer, and is told by his best friend Ned Schneebly (who he has been sponging off for years), that he has to start paying rent or move out, as Ned’s exasperated girlfriend Patty has had enough.

When Dewey takes a phone call offering Ned work as a substitute teacher at the prestigious Horace Green Preparatory School, he fronts up in Ned’s place, an hour late. Somehow, he manages to convince the strict principal Miss Rosalie Mullins that he can handle the job. Discovering that the privileged children – who are destined to go to Yale or Harvard and onto high-power jobs ­– can play musical instruments, when he finds them working on an aria from The Magic Flute with Miss Mullins, he has a light-bulb moment. He will get them to form a band, and perform with them at Battle of the Bands. In the process, he opens up a new world for the children, who feel their pushy parents aren’t interested in listening to them.

Amy Lehpamer and cast. Photograph © Matthew Murphy

The show takes a little bit of time to really kick in, but once the children take to the stage it lifts off. The story is pretty flimsy. The parents are sketchily drawn and their conversion at the end isn’t terribly convincing, while the happy outcome for Dewey also feels romantically far-fetched. If the performances weren’t firing, it would be a problem, but here you are having so much fun, you happily go with the flow.

Laurence Connor’s tight direction keeps the action flowing on the flexible set by Anna Louizos, while the costuming (also by Louizos) and the flashy rock concert lighting by Natasha Katz are a perfect fit.

Andrew Lloyd Webber’s songs may not be rock ‘n’ roll chart-toppers, but within the context of the show, they more than do the job, with Stick It to the Man, School of Rock, and Where Did the Rock Go? among the highlights. If Only They Would Listen, sung by some of the students, veers very close to sentimentality, but the children carry it off in a poignant moment.

Zane Blumeris and Brent Hill. Photograph © Matthew Murphy

It’s hard to believe anyone could be better in the role of Dewey than Brent Hill (a role so big, dramatically and vocally, that he shares it with Joe Kosky). He does a brilliant job of balancing Dewey’s slacker slovenliness and man-child selfishness with his obsessive passion for rock ‘n’ roll. He is dishevelled, obnoxious and yet still utterly endearing. Hill gives an uplifting, all-out performance. He rocks and rolls, he leaps around the stage landing rock star poses, he unleashes fierce vocals. His comic timing is priceless and he doesn’t play down to the children but meets them head-on dramatically, and they rise to the occasion in response.

There are three casts of children. On opening night, Zane Blumeris shredded the guitar in true rock star fashion, complete with power slides, Cherami Mya Remulta had plenty of attitude as bassist Katie, keyboard player Jude Hyland morphed from bullied dag to cool kid, Cooper Alexis let rip on the drums, Sabina Felias sang beautifully as Tomika, and Deeanna Cheong Foo ruled the roost as the super-organised Summer. But each and every child in the opening night cast was terrific.

Brent Hill and cast. Photograph © Matthew Murphy

Amy Lehpamer shines as the prim, uptight Miss Mullins, who is secretly a Stevie Nicks tragic, and raises the roof with Where Did the Rock Go? John O’Hara is suitably goofy as Ned, and Nadia Komazec makes the most of the thankless role of Patty (it’s a shame they felt the need to make the character so bossily shrill).

The on-stage playing is supported by a small, tight band in the pit led by Musical Supervisor/Director Laura Tipoki.

School of Rock is a fun, empowering show for the whole family; a real blast that sends you home smiling.

School of Rock plays at the Capitol Theatre, Sydney until March 1, and then at Adelaide Festival Centre, March 20 – April 12