The Spinal Tap poster.

Superfan Jim White, The Independen

There can only be one response to the news that legendary director Rob Reiner is planning a sequel to mark the 40th anniversary of his movie This Is Spinal Tap: please don’t. From the moment it was released in 1984, it was clear this film was something special — and over the years it has only grown in stature. Regularly appearing in authoritative lists of the all-time top 100 movies, in my opinion there can be no doubt: the Tap is the funniest film ever made. I admit this is probably not the sort of confession to be made in company, but I have watched the story of the hapless English heavy metal band attempting to make it in the US more than 50 times. Every time I sit down in front of it (and believe me, that is more often than is healthy) I discover something new in its comedy.

For every line that has become a classic — “these go up to 11”, “this one’s called ‘Lick My Love Pump,’” “have a good time all the time” — there are dozens of zingers that are just as good. “He died in a bizarre gardening accident,” “money talks and bulls*** walks”, “we’ve got a bigger dressing room than the puppets, that’s refreshing” and “you should have seen the cover they wanted to do, it wasn’t a leash believe me”.

What laughs it delivers — and what acute observation of the rock world. When Jeff Beck died, someone posted a video on social media of the notoriously camera-shy guitarist being interviewed. As he sat there chewing gum, not quite understanding the questions put to him, it became clear what lay behind the inspiration for Christopher Guest’s self-absorbed Tap strummer, Nigel Tufnel. So brilliant were all the characters in the film — from Michael McKean’s David St Hubbins and Harry Shearer’s Derek Smalls to Fran Drescher’s busy public relations executive Bobbi Flekman — that they developed a life beyond the confines of celluloid (Flekman even made an appearance in Drescher’s sitcom The Nanny, with Drescher reprising the role).

In 1992, Spinal Tap actually performed a concert at the Royal Albert Hall, delivering the songs from the movie, all of which are sufficiently well engineered to be at the same time ludicrous and yet entirely plausible. To promote ticket sales ahead of their gig, McKean, Shearer and Guest did a series of newspaper interviews. When I was sent by The Independent to a London hotel to speak with them, I expected to find a trio of comic actors talking about their creation. Instead, all three were in character and costume.

They were clearly having a ball, playing up to the moment, brilliantly improvising their way through their idea of a rock star interview, superbly articulating the essential mix of disdain and neediness that defines the process. It was an hour-long improvisation masterclass (Shearer ringing room service was comedy gold). And the picture I had taken with them hangs framed on the wall in my house to this day — the celebrity selfie to end all celebrity selfies.

The fun the threesome have together is evident in the half dozen movies they made since Tap. From the wonderful Mighty Wind to the sublime Best In Show, the Tap methodology found new and intriguing outlets. But there is more to the original film than astonishing characters, ridiculously funny situations and a superb — and largely extemporised — script. This was a perfectly edited piece of work. Being a Tap nerd, many moons ago I bought a CD box set. On it were about a dozen scenes which had not made it into the final cut. All were hilarious. All were telling. All would have easily fit into the theatrical cut, adding yet more depth and volume. Yet they hit the cutting room floor, removed not because they weren’t any good, but simply to ensure the movie flowed.