The massive LED video screen that forms the interior surface of Sphere can be used to transport audiences to the tops of mountains, to outer space, to beneath the feet of an elephant standing as tall as a 20-story building.

On Friday night, Phish turned the place into a car wash.

Playing the second date in a sold-out four-night stand at this state-of-the-art venue just off the Las Vegas Strip, the veteran jam band from Vermont took full advantage of the technological capabilities that cost the building’s mastermind, Madison Square Garden Entertainment Chief Executive James Dolan, five years and more than $2 billion to bring to life last fall.

At one point in the nearly four-hour gig, the 160,000-square-foot screen — said to be the highest-resolution in the world — became a starry night sky so crisply rendered that you could almost believe the roof had retracted; at another point, Sphere transformed into an underwater kelp forest with sunlight streaming down from the top of the dome. The venue’s sound system was just as impressive, with a finely detailed mix and seatback haptics that allowed you literally to feel the oomph of bassist Mike Gordon’s low notes.

Yet Phish’s production — the second by a band to play Sphere after U2’s opening engagement — wasn’t about excess or grandiosity; it was homey, friendly, deeply quirky. After the car-wash bit, which replicated the experience of crawling through one, a gigantic dog appeared and proceeded to lick what looked like the other side of the screen in slow motion as the band performed its song “You Enjoy Myself.”

The approach certainly differed from that of U2, whose 40-date residency launched in September and ended last month. Built around the Irish group’s 1991 album “Achtung Baby,” U2’s show riffed on big ideas about celebrity and media and the intersection of politics and capitalism; it used Sphere’s eye-popping tech to uphold the band’s distinct brand of rock-star heroism, reasserting U2’s place in a cultural lineage stretching from Frank Sinatra to Elvis Presley to the Beatles to Prince.

For Phish, perhaps music’s biggest cult band, Sphere wasn’t a means of self-glorification but of community-building: One thing you thought about over the course of the band’s two sets and an encore was how tiny the players looked onstage — the same size, in other words, as any of the 18,000 or so people in the crowd. Even when the screen would show a close-up of one of the players — Gordon, singer-guitarist Trey Anastasio, keyboardist Page McConnell and drummer Jon Fishman — the image would be warped almost beyond recognition.

Jam bands, of course, have a long history of elaborate visual presentations. Ahead of Phish’s run in Vegas, fans of the band wondered online whether its lighting designer, Chris Kuroda, would have the space to do his thing properly amid Sphere’s digital overload. (The answer was kind of.) So it makes sense that Sphere might become a destination for other acts in the tradition; indeed, next up at the venue is Dead & Company, which will begin a 24-show stint in May after saying that its 2023 tour would be its last.

Phish performs.

(Rene Huemer / MSG Entertainment)

With no fear of being overshadowed by the room, Phish leaned into Sphere’s immersive potential with an assortment of water-themed visuals: hundreds of swimmers floating in doughnut-shaped inflatables atop the waves of a rippling sea; marine life darting through the columns of a vast sunken monument; a psychedelic waterfall pouring over a cliff that seemed almost untouchably far away from wherever you were sitting in the steeply raked amphitheater. As part of a production team parked behind dozens of glowing monitors in the middle of the room, Abigail Rosen Holmes, Phish’s creative director, manipulated these images in real time, responding — sometimes subtly, sometimes dramatically — to the twists and turns of the band’s improvisations.

In a funny twist, Phish’s lack of anxiety about being upstaged by what was happening on Sphere’s wraparound screen — the members themselves seem well aware that they’ve never been much to look at — meant that Friday’s show actually felt like it was about music, which was clearly the point for a band that famously never repeats a set list.

“Bathtub Gin” was jaunty and playful, with McConnell threading a bit of Gershwin’s “Rhapsody in Blue” into the song’s fabric; “Lonely Trip” was a lilting ballad with one of the evening’s few convincing vocal turns from Anastasio. “Split Open and Melt,” which came just before the evening’s intermission, was the highlight of the concert: a demented boogie-rock freak-out that landed somewhere between early Sonic Youth and electric-era Miles Davis.

For its encore, Phish played the plaintive “Wading in the Velvet Sea” as photos stretching back to the band’s beginnings in the mid-1980s flickered across Sphere’s screen, and for a moment the musicians seemed to be indulging in the kind of rock-god mythologizing the rest of the show resisted. Then you realized that most of the pictures depicted these guys in various humble backstage scenarios: just four lifers getting ready to go to work for their people.