LONDON—Iggy Pop hobbles to the side of the stage at the Alexandra Palace, rocks back and forth on his shorter right leg like a high jumper who left his pole in the changing room, and bounds toward the microphone as the band kicks into "TV Eye." Shedding the formality of his waistcoat, and having omitted to wear a shirt, he contorts his bare, sagging, crepe-skinned but tanned torso and sings the blues.

"See that cat, down on her back," Pop bellows in a fruity baritone. He repeats the phrase, adding little melismata of variation as if he is seeing her in greater detail. But his perspective suddenly reverses on the third line: "She got a 'TV Eye' on me."

The repeated couplet and the surprise payoff are the basic triplet structure of the blues lyric. We hear a similar drama of sexual possession and technologically enhanced paranoia in Robert Johnson’s "Terraplane Blues," from 1936: "And I feel so lonesome, you hear me when I moan, / Who been drivin’ my Terraplane for you since I been gone?" The male possessor is possessed, unmanned by forces more powerful than his sexual desire.

"TV Eye" is modal, not chordal. Its tonalities and structure also owe more to the acoustic blues of the 1920s than the sleek rock of the 2020s. It rests on Ron Asheton’s simple guitar phrase, looped over a droning low A. Unplugged, this could be a Robert Johnson lick, a rubato counterpoint to the vocal that arises from the chording, stretches the meter, then drops back down into the song. Electrified, it could be one of those throwaway comments that the King Albert, Freddie, or B.B. might have appended between the lines. The Stooges, who recorded the original in 1970, turned an unconsidered trifle into an object of furious meditation.

The riff never stops. The bass doubles the guitar. The vocal often joins it. The whole band repeats a single phrase, as loudly as they can. This is the machine-press stomp of Detroit rock. The pounding sound of The Stooges is a steel-strung monument from the era when the Motor City still made motors you would want to drive. Closer in time to Robert Johnson than to us, it is an artifact of the age of mass entertainment and democratic art, and, though the other three Stooges seem not to have been aware of it at the time, a snapshot of 20th-century self-consciousness.

Pop’s eight-piece band are all young enough to be his children—some of them even his grandchildren. To hammer out this kind of music, you need the vigor of youth. Almost all of the setlist was written and recorded before they were born. We take this for granted when we go to hear Handel or Haydn. But we have also come to see as well as hear. Age has withered Pop, the years condemning him to a performance that his body can no longer manage. Like Sinatra preserving his voice, or James Brown going slow before falling to his knees, Pop has reduced his physical moves to kabuki evocations of his madcap prime.

The band curates the Stooges sound with the care of one of those Early Music ensembles that use Georgian cellos and cat-gut strings. Pop paces the show as the other old-timers did: a sprint that wins the audience, a pause to recuperate, and then a hard-pressed race to the end. The scorching opening trio of "TV Eye," "Raw Power," and "I Got a Right" leads a slow-quick pairing of "Gimme Danger" and "The Passenger," and then the knockout combination: "Lust for Life," "Death Trip," "Loose," "I Wanna Be Your Dog," and "Search and Destroy."

The band includes a keyboardist and a two-piece horn section of trombone and trumpet. Most of the time, these extras are drowned in the guitars, which is as it should be. Now and then, however, they suggest wider influences. The free jazz saxophone on "Fun House," from the second Stooges album, returns as a demented trombone solo on "1970," also from that album. The Jim Morrison vocal of "The Passenger" is framed by the Ray Manzarek-like tinkling of a Fender Rhodes. When the horns led the release on "Now I Wanna Be Your Dog," I realized that the sequence is lifted from the horn-led releases on Stax tracks such as "In the Midnight Hour." When Pop sits on a monitor and the band goes into "I’m Sick of You" at ballad pace with a noodling trumpet, we lounge in the territory of late-stage Sinatra’s "One For My Baby" routine—until the band tears it up halfway through.

Iggy Pop, who has played the fool all his life, grasped the nature of performance from, he says, seeing Jim Morrison in 1967, goading the audience almost at eye-level from a low stage. Pop fused this theater of excessive display with an antagonistic musical excess, the austerities of the endless riff. Pop was a contemporary of high-concept New York minimalists such as the transcendentalist hypnotists La Monte Young and the tape-loop pioneers Terry Riley and Steve Reich. The Stooges were as much an art project as the Velvet Underground, only much more groovy. The split consciousness of "TV Eye" expresses the split between Pop and the Stooges, the individual voice and the machine pulse.

Iggy Pop is not a person. He is a persona. James Newell Osterberg was born in Muskegon, Michigan, in 1947. He had loving, supportive parents. His father was a high school English and gym teacher in Dearborn. The family lived in a trailer park in Ypsilanti. When little James wanted a drum kit, his parents moved out of their bedroom so he could practice. The usual garage band apprenticeship followed when Pop enrolled at the University of Michigan at Ann Arbor, including with a band called the Iguanas, hence the nickname Iggy. He dropped out, picked up some more blues in Chicago, then formed the Stooges in 1968 with three local hooligans: the Asheton brothers Ron (guitar) and Scott (drums) and the bassist Dave Alexander. They surnamed him Pop after a local headcase who was also in the habit of shaving his eyebrows.

In 2014, Pop delivered a lecture at the BBC called "Free Music in a Capitalist Society." The only free music is free jazz, and that is because no one wants to pay for it. They do, however, love a freak show. James Osterberg never liked being called Iggy Pop. As Socrates was chained to his sexual drives, Osterberg is "chained to a madman." Like the lyric of "TV Eye," he has always acted out both roles at once. "I’m through with sleeping on the sidewalk," Pop sang on "Lust for Life," one of his plural comebacks under the supervision of David Bowie. "No more beating my brains with the liquor and drugs." The album cover showed Osterberg smiling in his high school graduation photo, as though unaware of the horrors that lay just ahead.

On stage, Pop insults the audience and Osterberg thanks them. It’s like watching King Lear and the Fool on the blasted heath, only played by the same character, and much funnier. The other three stooges were named for the Three Stooges. Pop’s spontaneous theater of cruelty was scripted by Osterberg’s conceptual theater of the absurd. "Here comes success!" Pop sang on "Success," also from the Lust for Life album, then takes the pratfall at the end, crying "Oh shit!" The horns and keyboards on "Some Weird Sin," another Lust for Life track, add circus jollity to Pop's tale of hope and disaster, and sound not unlike Madness (the English band, not the state of mind).

As Lucretius observed in De Rerum Natura, it is in the nature of things that someone else’s misfortune is comedy, while ours is tragedy. Pop’s slapstick is in the key of Baudelaire, touched by "a breath of wind from the wings of madness." The opening verse to "I’m Bored" could have been written by Groucho Marx:

I’m bored

I’m the chairman of the bored

I’m a lengthy monologue

I’m living like a dog

The last verse of "I’m Bored" turns the admissions of the first verse inside out, like one of Pop’s freak-show physical contortions:

I’m sick

I’m sick of all my kicks

I’m sick of all the stiffs

I’m sick of all the dips

Pop has reached the last stage of his dance with death. During the sexual boasting of "Loose," he has to be helped in and out of the pit. There is nothing funny about the finale, the doomy, teeth-grinding "Funtime," whose barker’s refrain "All aboard for funtime" sounds as if it comes from a deserted fairground.

Osterberg and Pop take the Lucretian view. In 1995, he, or they, became the first and presumably last rock star to write an article in a peer-reviewed journal: "Caesar Lives," published in Classics Ireland. The author describes how in 1982, "horrified by the meanness, tedium and depravity of my existence as a touring musician," he took recourse to Edward Gibbon’s Decline and Fall of the Roman Empire. The "grandeur of the subject" appealed, and the portrait of Gibbon suggested a "heavy dude." Music being a "political business," Osterberg already enjoyed gathering material for Pop’s career in political biographies. He saw himself in Gibbon’s tableau, and found inspiration for an album, American Caesar. He also saw us, seeing him:

I would read with pleasure around 4 a.m., with my drugs and whiskey in cheap motels, savouring the clash of beliefs, personalities and values played out on antiquity’s stage by crowds of the vulgar, led by huge, archetypal characters.

Iggy Pop gets wheeled off the stage. (Iggy Pop/X)

Pop ends "Funtime" like Lear, like Sinatra before the final curtain. A coffin is propped up in the wings, as it waited for Screamin’ Jay Hawkins, James Brown, and all three Stooges. The grandeur of the subject faces the absurdity of his predicament. To howling acclaim, Pop climbs in and closes the lid. As the coffin is wheeled across the stage, his hand appears, waving farewell. Then he flicks the lid open, laughing at his own joke and at death itself. We are still laughing as he disappears into the dark wings.

Dominic Green is a Wall Street Journal contributor and a fellow of the Royal Historical Society.