“But you have made whole records where you’ve only played one note,” Tony said. “So you were spoiled for choice.”

“It’s actually remembered as a virtuoso performance,” I said (sitting in, as they say in the jazz world, improvising with the Necks!). “O.K., I get what you’re saying. But how about if two of you are having a bad night? You can see where I’m going with this. How about if all three of you are?”

“You could get a perfect storm of negative elements,” Lloyd said, before it occurred to me that there was a corollary to my line of questioning. If they are all on good form, it still does not necessarily mean that it will be a great gig by the Necks. And needless to say, what they do is not to everyone’s taste. I reminded them of a gig in Brighton, England, in 2002 — the second time I saw them, before my conversion — when, the moment the first set ended, a member of the audience leapt to his feet and started hurling abuse, telling them and us what a bunch of crap it had been. (The guys took it with surprisingly good grace, seemed entirely unperturbed.) For the record, and to prove that I am not a mindless devotee, their discography contains a few duds: “Silent Night,” “Photosynthetic” and “Vertigo” do nothing for me. And a member of my little group at the Lab, having prepared for our evening out with a noseful of cocaine, was less than enthusiastic. “He does everything with those drums except play them,” he remarked of Tony, rather wittily. I was unsure, when he went on to say that seeing the Necks was just like seeing the Grateful Dead, whether he was joking, trying to make a serious point or testing the limits of my tolerance. Either way, coke is a wretchedly inappropriate drug for experiencing the Necks.

Impatience prevents you from seeing — hearing — that what you are waiting for is already happening (not a bad test-definition of the avant-garde). But there is scope for anxiety on behalf of the participating listener, because the gathering intensity is underwritten by the potential for dissipation. And any given performance makes you wonder how any part of it could be different. This is the possibility that the performance has to raise on the way to becoming that which it was. So the answer is always, Yes, it could have been very different, at almost every stage. Could it have been better? In retrospect maybe, but there are long interludes — sometimes lasting the entire length of the set — when you are left to reflect instead on how much was latent in that first note or chord or rattle of percussion. To what extent did that note — by Chris, say — determine what they all went on to do? The sense, in this genealogy of the moment, is of unanticipated inevitability.

Each set of the San Francisco gigs was extraordinary, as were the two closing sets of the tour at the Blue Whale a fortnight later. But how would these shows sound if they were released on CD? I’ve no idea. Some kind of bootlegged video of part of the previous year’s gig at the Blue Whale exists, but I’ve avoided watching or listening to it. I don’t want to have to measure my experience of being there — superlative! — against a transcript of what occurred. Setting the record straight can sometimes distort it. A performance by the Necks is all about band and audience being utterly absorbed in the process of creation. Whether to release recordings of live performances is therefore a fundamental conceptual issue. In the course of any performance of continuous improvisation lasting for the best part of an hour there are going to be lulls — substandard stretches that are left behind, that evaporate and are forgotten as a show progresses, but that can fatally contaminate an entire recording. And as Lloyd points out, the orgiastic bits — which are so intoxicating live — can seem crude. More broadly, a record becomes a statement or template — this is what the Necks do — whereas it is merely a record of what happened that one night. Even without the problem of releasing live albums, it’s important that the band is not overly concerned with analyzing their live shows; the quality of performance depends on this relative indifference. The kind of post-mortems they go in for after a show typically amount to something along the lines of “That was pretty good wasn’t it?”