Now rightly regarded as a cult classic, This Is Spinal Tap is probably the finest spoof rock documentary ever made, and a master class in satire. Directed by Rob Reiner and released in 1984, the film wasn't an immediate hit, but a slow-burner. Audiences initially found it hard to distinguish the spoof from the truth, as the film was way too close to the real-life British heavy metal bands and hard rock groups that it satirises.
But now, more than 20 years later, the film's comedic power is easier to appreciate, especially as many of the bands and musicians that it apes have split due to musical differences, audience apathy or died in bizarre circumstances.
The film - which traces ageing heavy-metal UK rockers Spinal Tap as they perform a comeback tour of America to promote their latest album - was the brainchild of comedians, writers and actors Rob Reiner, Christopher Guest, Michael McKean and Harry Shearer.
All four have parts in the film. Reiner plays Marty DiBergi, the film-maker who wants to present a documentary - or "rockumentary" if you will - of Spinal Tap. He interviews the three key members of the band - rhythm guitarist David St Hubbins (McKean), lead guitarist Nigel Tufnel (Guest) and bassist Derek Smalls (Shearer), following them as the tour progresses, slotting in concert footage and updating the interviews as he goes. Along the way he meets Tap's other members, their management and their support crew.
Guest, McKean and Shearer turn in outstanding performances, so deeply immersed in their roles that it's hard to believe that they are actually American comic actors, spoofing British heavy-metal musos. And there's some excellent support performances too, especially June Chadwick as St Hubbins's girlfriend Jeanine Pettibone, Tony Hendra as Tap's long-suffering manager Ian Faith, Fran Drescher as slick marketing woman Bobbi Flekman and Paul Shaffer as flustered PR Artie Fufkin.
And it's all neatly linked by some hysterical set pieces, such as "Stonehenge" (much loved by Sting, apparently), "Sex Farm" (at the US air base) and "Rock n Roll Creation" (with the malfunctioning pod).
If you've never seen This Is Spinal Tap before, then you're in for a real treat. And if you have seen it before, the film bears repeated viewings, with its many layers of intricate detail to enjoy.
Just make sure you're watching it in Dubly...