WATCHING American Idiot is exhausting! It’s a full-on show, with the young cast barely taking a breath between frantic numbers, and it’s so in-your-face it’s like being shouted at for two hours.

The rock musical, inspired by Green Day’s Grammy-winning concept album, is set in post-9/11 America, taking the well-trodden path from sleepy suburbia to big city. It’s a story of youthful mistrust and restless rebellion, as three boyhood friends search for meaning. One joins the army, another gets stuck in a rut of young fatherhood and Johnny, the main protagonist, descends into hellish drug addiction.

Green Day have been around long enough for me to know their songs - Boulevard of Broken Dreams, 21 Guns, Wake Me Up When September Ends and the riotous title track among them - that form the backbone of this show. And I get the whole youth disillusion thing, (Johnny’s middle finger was flipped so many times you couldn’t fail to get it), but I found myself not really caring. The guys, with their endless angst, seemed a bit childish, while the show’s females served little purpose. In one scene they were simply cheerleaders.

Fast-paced and chaotic, with little dialogue, it whipped along in a rock-fuelled frenzy but I’m still not sure what it had to say. As my niece said, at the end of Act 1: “It’s basically like watching a Green Day concert.”

To her, this was no bad thing, as she’s been a fan since childhood. And to other Green Day devotees whooping in the audience, this is a show that clearly has a lot to say. Its themes of youthful disillusion are relevant, particularly in America where schoolchildren have campaigned for gun law reform, and in the UK where they’ve skipped class to stage environment protests. Although from where I was sitting, Johnny and his mates were more into hedonism than protesting...

It’s a fabulous-looking show; designer Sara Perks’ stark set is brought vividly to life with inventive props helping to shift the action at breakneck speed. An impressive band onstage creates the rousing rock vibe.

The cast is headed by local actor Tom Milner, terrific as Johnny, whose cocksure swagger wanes as he slides into an abyss of addiction. Tom has a beautifully charismatic, almost fragile stage presence.

Luke Friend, alumnus of Shipley’s Debut Theatre School, was mesmerising as menacing drug-induced alter-ego St Jimmy.

Great performances too Joshua Dowen as Tunny and Samuel Pope as Will. Sam Lavery has a powerful voice but was under-used as the love interest, Whatsername.

Like many rock musicals, American Idiot feels a bit dated. But the energy and performances of this cast are first-rate.

Runs at the Alhambra until Saturday. Not suitable for under-14s.