However you feel about bloated rock concept albums, it’s hard to argue that this isn’t the definitive one. The record produced a number of hits, a bizarre tour, and a few genuine moments of utterly incomprehensible bad-ass-ness, one of which occurs at the 4:30 mark here. Up until this point, The Wall has veered all over the fucked up map of Waters’ life, run through a gauntlet of abusive headmasters, doting mothers and vacuous girlfriends, some absurd, some poignant, all of them stewed in a pot of awkward ambivalence. Comfortably Numb, sweet and sad, begins to distill this mess into genuine pathos and beauty. At least that’s how it starts.

But then here, at 4:30 or so, just as Waters hammers a bass note so leaden and abused that he must have plucked the string with Australopithecus’ preserved femur, a note viciously kicked in the teeth and shoved into a storm drain, a note that floats for one wispy second like a severed head on a post, a stark warning of where you’re about to go – here, right here, this is where the record plunges over a cliff into a sea of dark madness. It’s a second or so of mood change so intense that when you hear it, you realize, FUCK, this is what this entire album has been leading up to. This is the killshot, the knockout, the epiphany. This is Alec Guinness staring at that goddamn bridge, mumbling “what have I done,” and collapsing.

Back when this record came out, it was, well, a record, and Comfortably Numb ended side three. You flipped it over after this to what was, in essence, a climax of destruction followed by a strange little denouement. But that moment, that change at 4:30, that’s the peak of this record for me. Gilmour follows it with possibly the most gorgeous, sinister solo of his career, and it fades into disaffection, alienation and insanity. Beautiful.