LAS VEGAS – As the second band to play the Sphere following a triumphant 40-show run by U2,John Caldwell Phish had a high bar to clear.

The band – Trey Anastasio, Jon Fishman, Mike Gordon and Page McConnell – kicked off their four-show run April 18 with the mellow groove of “Everything’s Right" and kept rolling for four trippy hours presented in two sets and an encore. But the focus was as much about what the eternal jam-rockers would do in the enveloping arena as the adored band itself.

Towers of lights (on video) weaved and danced around the walls of the Sphere like a screensaver for the opening song. The visuals then expanded across the width of the mammoth curved walls with scenes of beaches and grassy expanses during “Back on The Train.”

Phish made clever use of the surroundings, whether mesmerizing with repetitive swirls of shapes or sending lighted fabric pods toward the roof during the ethereal “Leaves.” Floating antenna TVs, silhouettes of the band members in film-negative form, spectacular bursts of color and cars morphing in size and shape complemented songs including "Life Saving Gun" and "Tweezer."

Anastasio recently told SiriusXM that he wanted a "psychedelic" experience for fans attending the shows. Mission fully achieved.

But for a band more about music than personality, the quartet, which sounded crisp, could sometimes blend in with the oval stage and awe-inducing graphics. During the first set, Anastasio’s vocals were often difficult to decipher, but the multi-generational crowd eagerly compensated until the mixing was tweaked and the immersive sound kicked in.

Phish's sold-out Sphere run continues Friday, Saturday and Sunday. While the venue's website notes that these are the first performances of a "new relationship" between Phish and the Sphere, they are the only 2024 dates the band will play there.

A word of caution: Entering the venue can be a slog. It took a solid hour leading up to Thursday’s show for the herds of fans to inch their way toward the entrance down poorly ventilated hallways, so prepare accordingly.

Also, as even casual Phish followers know, the band will mix up their setlist for each show, presenting not only a unqiue run of material, but specialized graphics every night. Here is a look at the songs from their epic first Sphere concert.

More:Mariah Carey's new Vegas residency manages to be both dazzling and down-to-earth

Phish's opening night setlist at the Sphere

Set 1

“Everything’s Right”

“Back on the Train”

“Wolfman’s Brother”

“Maze”

“Leaves”

“Life Saving Gun”

“Dirt”

“Carini"

Set 2

“Sand”

“Tweezer”

“My Friend, My Friend”

“Mike’s Song”

“Lifeboy”

“Weekapaug Groove”

“Blaze On”

"Fluffhead"

Encore

"Farmhouse"

"Run Like An Antelope"