Punk rock isn't supposed to sound this great 40 years on. Is it?

I'm talking about X, the original quartet from Los Angeles, on Wednesday night at First Avenue. From the get-go, X bassist/singer John Doe remarked that Wednesday must be the night to play at First Ave.

From the get-go, X was on fire. Doe and Exene Cervenka harmonized like no other punk singers ever did. D.J. Bonebrake pounded away with precision and force on the drums. And bespectacled blond Billy Zoom enthralled with his array of guitar stylings from rockabilly and swingabilly to surf and Hawaiian and, of course, speedo punk. His right hand was so fast I thought I would get RSI by osmosis.

His playing was so guitarlicious that you didn't even mind that the 69-year-old was no longer able to stand in his distinctive spread-legged pose. A recent bout with cancer has forced him to sit on a stool.

And don't underestimate the lyrics of Doe and Cervenka. Arty for sure, though maybe not as poetic as Patti Smith. And often just as clever as anything the Ramones or the New York Dolls ever came up with. Song titles like "Your Phones Off the Hook But You're Not" and "The Once Over Twice" speak for themselves.

At 61, Cervenka remains a powerful presence, an unrestrained artist who is comfortable donning the T-shirt of X's opening act (Skating Polly), to accompany her red cowgirl skirt and tall cowgirl boots. Loved the way her arms danced to Zoom's solos.

Doe, 64, her ex-husband who has had a fruitful career outside of X, throbbed away on the bass and held his own on lead vocals. The way his and Cervenka's voices intertwined added to X's distinctive sound.

The quartet's 90-minute set didn't feel like punk as professionals the way the Replacements reunion tour did in 2014-15. There was a consistent vitality, urgency and timelessness to X's performance.

Bonebrake played vibes on a few songs (with a sideman sitting in on drums), helping to change the pace and texture. "I Must Not Think Bad Thoughts" was nicely layered with vibes and saxophone (played by Mr. Zoom), and vibes helped frame the moody, "Twin Peaks"-ish "The Unheard Music."

But the full throttle punk is what drove the capacity crowd crazy: "Los Angeles" felt like a dangerous 100 mph ride on an L.A. freeway; Cervenka nailed "Your Phones Off the Hook"; Doe knocked "Johnny Hit and Run Pauline" out of the park as Zoom attacked his whammy bar; "Motel Room in My Bed" was pure punk chaos, topped off by a version of the Doors' "Soul Kitchen." (Remember the Doors' Ray Manzarek produced X's 1980 debut, "Los Angeles".)

The encore kicked off with the country-punk stroll "The New World," followed by the metal-ish "Nausea" (Zoom can play in so many styles) and "Devil Doll" with the guitarist doing runs up and down his fretboard.

It sounded that great 40 years on. Yes, X did.