Dead & Company keeps the spirit alive at Fenway

John Mayer and Bob Weir performed with Dead & Company at Fenway Park. Barry Chin/Globe Staff/Globe Staff/file

The Grateful Dead refuses to go gentle into that good nightfall of diamonds.

Fifty years after the band’s founding, 20 years after Jerry Garcia’s death, and months after American popular culture gave the godfathers of improvisational rock a reverent wet kiss over the course of three supposed “farewell” shows last summer in Chicago, a new formulation of the band rumbled into being and hit the road again in October.

With John Mayer, veteran of the pop charts and tabloid pages, joining surviving Dead members Bob Weir, Mickey Hart, and Bill Kreutzmann — bassist Phil Lesh was indeed finished with on-brand reunions after Chicago — an ensemble with legit claims to the Grateful Dead’s intellectual (and ineffable) property was born anew.

Aside from “Black Muddy River,” which the Dead debuted in 1986, the entire setlist of Dead & Company’s show at Fenway Park on Friday could have been played in 1977. So is the music good enough to justify the nostalgia? Absolutely.

This show was better than it needed to be, maybe better than it really had any right to be. Even if there’s a ceiling on the level of psychedelic mayhem this band can (or wants to) generate, there was no shortage of sparks kicked up in a filling evening of music.

The centerpiece was an elegantly crafted second set, which opened with a thunderclap in “St. Stephen” before yielding to “Dark Star,” the Dead’s moody, hallowed showcase for interstellar alchemy. Across 18 minutes, the song waded into its customary dark waters before veering into an earthy rave-up informed by the band’s country-rock leanings. The left turn proved as satisfying as it was surprising.

Ringer bassist Oteil Burbridge (lately of Allman Brothers Band) offered a technically proficient solvent all night that bound together the rhythms of drummers Hart and Kreutzmann. Longtime “zombie Dead” sideman Jeff Chimenti added bright colors on organ and piano. But the news here is that Mayer’s bluesy guitar leads suit the material well; he led an upbeat, dawn-breaking jam in “Space” and earned a titanic peak in “Morning Dew.”

When Mayer took lead vocals in a majestic “Terrapin Station,” as the glowing moon hung above the grandstand on the first base line, there was the lingering sense that this whole ritual is always a little bit off with the ever-echoing absence of Garcia.

But songs will endure. And this spell-casting performance argued doggedly that the music never stops.

Dead & Company

At: Fenway Park, Friday evening