The trailer makes this comedy outing look like an ill-advised mish-mash of School of Rock, Josie and the Pussycats and Spinal Tap, and that's at least partially true. It's certainly wearing its influences on its sleeve, but as it happens its reasonably funny. Go figure.

Robert 'Fish' Fishman (Rainn Wilson) is a bitter, bitter man. Booted out of hair metal band Vesuvius just as they get their big break, the drummer replaced by their new record label's bosses nephew, normal life has never quite sat comfortably with him. Booted out of his job after another Vesuvius related temper tantrum and kicked out of his girlfriend's home, he's at a low ebb as he begs a bed in his sister's attic.

However, an opportunity to pick up the sticks appears when his nephew's band has their drummer expelled from school leaving their prom night gig in doubt. Fish is persuaded to fill in, and despite a less than cohesive performance manages to convince the rest of them to allow the old guy another chance banging the skins.

And so it goes, as the band rise to the top surprisingly quickly off the back of some decent tunes and an unfortunate YouTube viral of 'The Naked Drummer' the details of which you can probably gather from the title. Thereafter, gigs, tours, video shoots and interband strains, the general outline of which you're probably familiar enough with to write yourself, let alone imagine it.

While it might seem familiar, its saving grace is that it's pretty funny. The role might seem to be calling for a Jack Black type performance from the lead, and while Rainn Wilson, star of the Yankee version of The Office does head off in that direction occasionally (i.e. getting drunk, falling over) the crucial difference is that he's genuinely likeable even when he's acting like a spoilt ten year old, and even funny when making disturbing threats about attacking people like a rabid wolverine and chewing their face off.

The script is sharply written, with some unexpected leftfield interjections of humour mainly from Fish's nephew Matt, who occasionally speaks in ways that seems to have been designed specifically to amuse me. The cadence and wording of the line "I heart Matt le Blanc from T.V's The Friends" is custom built to tickle my perversions of language structure.

All in, there's a good mix of broad comedy, which is less successful than the rest of the film, and some fairly cutting remarks that ought to keep a wide audience range happy. Even, dare I say it about a film where people bang their heads and fall over so often, there's some subtlety about it. It's clear that the troubled lead singer Curtis and sassy guitarist Amelia have fallen for each other but are too nervous to broach the subject from the looks their giving each other, but it's never inflated into some drama or even spoken about until it's dealt with almost as an aside during the ending. Okay, it's hardly Shakespeare, but given that overblown hysterics would normally be expected from things of this ilk, it's commendably restrained.

Another point of note is the Pete Best cameo, who is perhaps better known as the Beatles ex-drummer, kicked out of the band by their producer just before recording their first album, a story which may perhaps sound somewhat familiar.

All in all, The Rocker is surprisingly enjoyable. It's not Spinal Tap, but then what is? Apart from Spinal Tap, of course, which couldn't be any more Spinal Tap. None more Spinal Tap. The only real criticism I've got is that it's a little derivative and could use a bit less falling over, but other than that I'm quite happy with this film.

Were I in the business of passing quantifiable judgements, I'd award this 4/5 TippyMarks.