DARIEN — The question was never, “How good would they be when they finally got back together?” The question was simply, “How far would they be able to take it this time?”

Were there new mountains to climb for Phish, the world’s biggest “jam band”? Or would this just be a cash-in on the abundant and loyal audience that filled Darien Lake Performing Arts Center to capacity Thursday?

As it turns out, this band has the world at its feet. It could go anywhere the collective imagination of its members might deem worthy of investigation. Or it could implode, splinter into the various solo projects its members have indulged in over the past five years.

Not knowing what might happen is half the fun. Who knows? This one might be your last Phish show. The lack of ease and the absence of the comforting glow of habit glared brightly above Darien Lake on Thursday. Both worked together to make it a show that, when it wasn’t downright transcendent, was several comfortable miles from the average.

The place was sold out, and the parking lot packed with folks hoping for a miracle. The communal, familylike atmosphere of Grateful Dead shows in the latter ’80s and early ’90s pervaded. Everyone seemed to be happy about something, and despite the sheer numbers, the atmosphere was friendly.

That’s because Phish fans, generally speaking, are there for the music. The party surrounding tends to be treated as secondary to the band itself. This has immediate and obvious appeal. People are chill. They just want to dance, and high-five their bud when the band plays a deep album cut that hasn’t yet appeared on the set lists of this tour.

It was obvious from the beginning that this would not be a mediocre Phish show. The band walked onto the stage casually, acknowledged the rapturous roar of the crowd with what appeared to be genuine, surprised appreciation, and tore directly into “A Sample In a Jar.” Right off, the Phish blend of Latin rhythms, the polyrhythmic flexibility of progressive rock and genuine songwriter’s craftsmanship was apparent.

When guitarist and vocalist Trey Anastasio took his first solo of the evening, the place erupted, and rightfully so; Anastasio worked jazzlike, repetitive and understated figures into a jaw-dropping solo. He had hinted at what was to come—a guide for the modern guitarist toward a new way of playing inside, around, beneath, between and behind chord changes. For the nonmusicians in the house, this meant dancing, and basking in the jubilant glow of the sound summoned by Anastasio, keyboardist Page McConnell, bassist Mike Gordon and drummer John Fishman.

“Dinner and a Move” followed and introduced the Zap-pa-esque side of the band. A blend of surrealism and bizarre, jazz-based chord changes led into another supple Anastasio solo.

“Wolfman’s Brother” took off like an unbreakable horse out of the stalls, then skillfully dissolved into a fiery take on Miles Davis’ “Jean Pierre,” before returning home to its familiar theme. The wholly unexpected “My Friend, My Friend” followed, and it was across the expanse of this song’s luxurious chord progression that Anastasio earned the crowd’s full respect. His solo was astounding, an aural equivalent of watching an Olympic athlete at work. Wow. Anastasio plays off of drummer Fishman, then feeds it back to Gordon and McConnnell. The result is a swirling form of give and take, a firm commitment to making something happen in the moment.

“Possum” gave Gordon a chance to shine in the lead vocalist role, and again, Anastasio seemed to be urging the others toward something that, perhaps, they hadn’t yet explored. This made everything feel electric, pregnant and exciting.

Phish revealed its pure, folk-based songwriting smarts with “Farmhouse” and then fell into a pair of “tribute songs.” The first, “Brian and Robert,” is a nod to Eno and Fripp; the latter, “David Bowie,” was a beautifully obtuse gift to the man himself.

The first set of Phish’s gig at Darien Lake was beyond reproach. Outstanding. There is an awful lot of life left in this ensemble.

Concert Review

Phish

Thursday night at Darien Lake Performing Arts Center.