Rob Reiner is the multiplex auteur par excellence. His career is marked by fruitful collaborations with the best screenwriters in Hollywood, creating some of the most memorable scenes in the history of American cinema. He gave a late-twentieth century inflection to some of the genres of the 1950s and the influence of some of his output is still being felt in the few Hollywood productions that are aimed at grown-ups. The recent obituaries for Nora Ephron have noted how WHEN HARRY MET SALLY (1989) both revived and changed the romantic comedy and the dialogue in Aaron Sorkin’s A FEW GOOD MEN (1992) and William Goldman’s THE PRINCESS BRIDE (1987) sparkles with wit.

It’s interesting that his most accomplished film is one that includes mostly improvised dialogue and created a genre of its own. There had been other ‘mockumentaries’ before this, the film owes a certain debt to ALL YOU NEED IS CASH (1978), the brilliant parody of The Beatles by Eric Idle and Neil Innes as The Rutles, but THIS IS SPINAL TAP is the benchmark against which all others need to be judged.

The world’s loudest band is captured on film as they undertake an American tour to promote their latest album Smell The Glove. Footage of their doomed performances is interspersed with interviews and behind the scenes footage, with more quotable routines than a skip full of dead parrots. Its the improvised scenes between Nigel Tufnel (Christopher Guest) and Marty diBergi (Reiner, as a spoof Scorsese) that I enjoy the most now, but it wasn’t always the case.  I first saw this film on VHS during an eventful all-nighter in 1986 which was ram-packed with fine quality cult films, many of them will make an appearance on here at some point, but this was the film out of them all that I adored instantly because of the hilarious stage shows. I don’t know which scene is the funniest: Derek Smalls (Harry Shearar) trapped in a transparent pod or the sight of ‘little people’ dancing around a miniature Stone Henge.

They have tried to revive the franchise with tours, books and television specials – the DVD commentary is one of those rare ‘worth listening to’ ones – but they have never been able to capture the brilliance of this film. They miss the vital ‘Reiner Factor’.