Christopher Guest would like you to know that there was no particular band that inspired Spinal Tap — not that this discouraged audience members from positing theories at last night’s 30th anniversary New York Film Festival screening of This Is Spinal Tap, even after Guest insisted that none of them would hold. It had to be inspired by Uriah Heep, one man insisted (based on that band’s high drummer turnover rate). Another said it had to be drawn from Michael McKean’s time in the pop band The Left Bank.

“This was not about a specific band,” Guest explained patiently, more than once. “But it’s that weird thing that after the fact, dozens of bands would come up and say, ‘That’s me.’ ‘It’s not you.’ And people would say, ‘You’re doing Jeff Beck,’ and Jeff Beck said, ‘You’re doing me.’ No, no, I’m just me, doing this other thing. But it is interesting, how after the fact, it becomes some other animal.”

That said, there was a particular incident that may have sparked something in Guest, who co-wrote the script (what writing there was — more on that later), co-wrote the songs, and co-stars as Spinal Tap’s lead guitarist, Nigel Tufnel. “In the ‘70s, I was in LA, in the lobby, waiting for a friend at a hotel,” Guest recalled. “And a British band came in, and the manager went up to the desk, and he was checking in. And he turned, and one of the musicians was standing there, and he said, ‘Where’s your bass, where’d you put your bass?’ ‘I don’t know.’ ‘What do you mean?’ ‘I think I left it at the airport.’ ‘You left your bass at the airport?’ ‘My what?’ ‘Your bass. Where’s your bass?’ ‘I don’t know, do I?’ This went on for 20 minutes. ‘So you’re saying you left your bass at the airport?’ ‘Well I don’t know, do I?’ And I guess somewhere in my head, this lodged into some kind of bizarre one-act play, where this circular thing just kept going around. But there’s no specific thing — it’s really much more interesting to create, from the ground up, these people.”

Guest and McKean started writing songs together long before Spinal Tap, back in their late teens, but Spinal Tap didn’t come together until 1979, as part of sketch comedy special called The T.V. Show (with, interestingly enough, Loudon Wainwright on keyboards). “A few years later,” Guest recalled, “we thought, this was fun, why don’t we continue doing this. And we were given money to write a script, and we realized about a week later that we couldn’t really write what we needed to do — it needed to be done in a more spontaneous way. And so we took the money they gave us, and we started actually making the movie.”

It’s common knowledge, by now, that Spinal Tap is improvised (as were Waiting for Guffman, Best in Show, and A Mighty Wind — the Guest-helmed films that followed in the same style), but that description is deceptive; the films aren’t as totally up in the air as you might think. “We wrote an outline, which delineates all the scenes, and all the complexities of what happens in the movie, and then we shoot. There are no rehearsals, and there’s no lines written. And apart from specific jokes — like the ‘11’ joke, because we had to make the amp — it’s all on camera.” And that time on-camera is actually miniscule compared to the difficult, labor-intensive part of the process: editing. “We shot 50 hours of material; the film is 82 minutes. It took almost two years to edit. And the films that I’ve directed, it’s virtually the same ratio — I shoot for roughly 25 days, and I edit for a year and a half. It’s an upside-down process, in a sense.”

Guest said that last night’s NYFF screening was the first time he’d watched the movie in “I think about 12 years, roughly. I’ve only seen it a handful of times.” And while he was nervous about revisiting it, he enjoyed one element in particular. “I like the scenes where we’re all interacting, because it’s improvised, and you see people kind of playing music with each other… it’s more like a musical group playing and weaving in and out.”

Making a film that relies on that improvisational byplay is a risk — but the kind of risk that pays off beautifully here and in Guest’s other work. Though Guest didn’t discuss why he hasn’t directed a film since 2006’s For Your Consideration (his most recent work was the HBO series Family Tree), he did talk about the difficulty of finding people who will take those risks. He says Spinal Tap was turned down by pretty much every major studio (“People said, ‘No, this is — I don’t even know that this is”); it was finally financed by Norman Lear, the groundbreaking television producer behind All in the Family and The Jeffersons, among many others.

“If it hadn’t been for Norman Lear,” Guest said, “there would have never been a movie, because he was the only one who said, ‘Just go and do this,’ and he trusted Rob. And then years later, when a company called Castle Rock was formed, Rob Reiner said to me, ‘Just go and make a movie,’ and I made a movie called Waiting for Guffman, and then I made several more. That doesn’t happen anymore, where someone says, ‘Just go and make your movie.’ Rob was lucky to have Norman as his patron, and I was lucky to have Rob as my patron.”

NYFF Photo Credits: Jason Bailey / Flavorwire