An Eagle landed on the War on Drugs’ ‘A Drugcember To Remember.’ Neither the flying kind nor the playing kind.

During the second night of the War on Drugs’ three-show “A Drugcember to Remember” run at Johnny Brenda’s on Friday, there were two kinds of special guests.

The first was deeply satisfying, really cool, and not entirely unexpected.

It was Craig Finn, the front man for the Hold Steady, whose superb new album, Always Been, was produced by Drugs leader Adam Granduciel.

Finn does have a track record of showing up at Drugcembers past, so the second guest was a tad more surprising.

It was a genuine “Holy [cow]! What just happened?” moment that gobsmacked a crowd that was already pinching itself — it’s not every day you are lucky enough to see Philadelphia’s most acclaimed rock band in peak form in a 250-capacity room, many times smaller than the capacious spaces they play in around the world.

It was Joe Walsh. Yes, that Joe Walsh, the James Gang founder, solo artist, and guitarist for the Eagles — the band, not the football team.

He joined the Drugs for a three-song finale that capped off a masterfully executed two-hour, 15-minute show that benefited the Fund for the School District of Philadelphia.

But the night would have qualified as an unforgettable Drugcember to Remember even without the out-of-the-blue rock star appearance.

The show’s earlier highlights included a roaring cover of Tom Petty’s “Love is a Long Road” and a goose bump-inducing 17-minute motorik version of “Harmonia’s Dream,” from the band’s 2021 album I Don’t Live Here Anymore, that spotlighted keyboard player Robbie Bennett.

It leveled up to a higher plane with the arrival of Walsh, the 78-year-old powerhouse slide guitar player who seemed thrilled to be playing with a decades younger vise-tight group of simpatico musicians.

The Walsh-Drugs mini-set kicked off with “Rocky Mountain Way,” the extra-crunchy 1973 hit that turned Walsh into a solo star. He was joined by an arsenal of guitarists onstage including Granduciel, Anthony LaMarca, and, at times, newest band member Eliza Hardy Jones, who also played percussion and sang backup throughout the evening.

On “Rocky Mountain Way,” which has gotten new life in the last year as a TikTok phenomenon, Walsh employed a talk box, using a tube in his mouth to manipulate and distort the sound of his guitar in ways that still sound futuristic 50 years later.

It also meshed perfectly with the audio geek aesthetic of Granduciel, who is an expert at layering guitar and keyboard sounds to transporting effect.

Before the band leaped into that song, though, Granduciel and Walsh explained to the nonplussed crowd how the seemingly unlikely collaboration came to be. How did Walsh wind up onstage at the Fishtown club that has been the Drugs’ spiritual home since they played there on the venue’s opening weekend in 2006?

Here’s the story: In 2023, the band played Walsh’s VetsAid concert for military veterans in Los Angeles.

“We became friends, we stayed in touch,” Granduciel said. “And he wanted to come to Drugcember, he wanted to see all you guys. He wanted to breathe the air that we’re breathing.”

During the Drugs’ set at VetsAid, Walsh said, “I was walking around backstage and I listened to ’em. And I never heard them live. They make nice records. But, boy, this thought: I couldn’t help it. ‘Damn! I’d sure like to play in a band like that.’ Be careful what you … wish for!”

“Rocky Mountain Way” was followed by “In the City,” Walsh’s song written for the 1979 action movie The Warriors that he also recorded with the Eagles. His craggy and Jones’ dulcet vocals made for a captivating blend, while the rhythm section of bassist Dave Hartley and drummer Charlie Hall powered the song forward.

As exciting as it was to hear the Drugs back up Walsh on his own hits, it was more compelling still to watch him engage with the band on the closing number of the night, “Under the Pressure,” from 2014’s Lost in the Dream.

That song is combustible under normal conditions, but it moved from a simmer to a boil in a flash with Walsh added to the mix. He and Granduciel were hunched over their guitars on the lip of the stage, illuminated by the strings of holiday lights on the mic stands and on the balcony railings above them in the intimate club.

It was like a one-of-a-kind Fishtown version of what Keith Richards and Ronnie Wood of the Rolling Stones call their “guitar weave,” and it was a kick to watch Walsh so enthusiastically just want to be one of the boys in the band.

As mentioned, pre-Walsh, the show was terrific on its own terms. And a special shout out goes to Jon Natchez, the Drugs’ multi-instrumentalist, who played keyboards and baritone sax.

The latter instrument’s honking added extra force to typically meticulously arranged songs like the Phil Collins-evoking “I Don’t Wanna Wait,” a highlight of the band’s opening set, which was followed by a 15-minute intermission.

In introducing Natchez, Granduciel mocked his Boston sports fandom. “He wouldn’t be caught dead in an Eagles jacket,” the bandleader said. “I’m out of Boston, too” — Granduciel grew up in Dover, Mass. — “but I bleed green.”

The evening began three hours before it ended with Finn walking onstage with an acoustic guitar and wearing a Natural Light ball cap. He warmed up an attentive crowd with songs and stories, mostly from Always Been, his superb song cycle that’s partly set outside Philadelphia and mostly at the Delaware shore.

Finn was followed on stage by seven members of the Drugs, who reached back to open with “Arms Like Boulders,” from the band’s 2008 debut Wagonwheel Blues.

“Pain,” from 2017’s Grammy-winning A Deeper Understanding, outlined the idea of the unending quest that’s an animating concept in Granduciel’s lyrics. “I want to find what can’t be found,” he sang. And later, in “Strangest Thing,” also from Deeper, he sang about still not finding resolution: “I’m just living in the space between the beauty and the pain.”

Seven songs in, the Drugs brought Finn back out for a three-song interlude that closed the first set.

Two of those were from Always Been, including the engrossing “Bethany,” which took off into the stratosphere with a Granduciel solo midway through. Then it lingered with an image in the closing line: “But the sunset looks like blood from the window of the bus, somewhere between Harrisburg and Bethany.”

The third song in the Drugs-Finn collab on Friday was “Sweetheart Like You,” featuring Finn and Granduciel trading vocals on Bob Dylan’s philosophical barroom come-on.

That was a treat, with Finn being very much himself, gesticulating his way through his verses while Granduciel slipped into his best sneering Dylan voice. It was an exquisite combo, and just one of many indelible moments in an evening that for all concerned will surely be the Drugcember they remember.

The final sold-out night of “A Drugcember to Remember” was scheduled for Saturday night at Johnny Brenda’s. No special guests have been announced.