Like a young relative you see only occasionally, Dead & Company seems to grow by leaps and bounds in between its annual summer tours.

When the group started, it lacked cohesion and was compelling mostly because it featured Grateful Dead members Bob Weir, Mickey Hart and Bill Kreutzmann playing Grateful Dead music along with keyboardist Jeff Chimenti, bassist Oteil Burbridge and, unexpectedly, guitarist John Mayer. Four years down the line, Dead & Company are compelling because they’ve gotten really good at extending the long strange trip that by all rights should have ended years ago with a strong mix of nostalgia and contemporary music making.

Exhibit A: Set 2 of the band’s performance at the Rouff Home Mortgage Music Center – that’s Deer Creek to everyone but the corporate sponsor – which began with Burbridge singing “Fire on the Mountain.” Unusally, the song flared up from a dead start and wasn’t paired with its usual partner “Scarlet Begonias.”

Mayer used the familiar effects of a certain bearded axeman to give the song a Grateful vibe, while the former Allman Brother’s voice gave it the stamp of something new.

Next, “Lost Sailor.“ This is one of those Dead songs that sounds nearly the same in this group’s hands as it did in the father group and Weir, recently slimmed down and jacked up, gave it an impassioned reading as he led the group to “Sailor”’s first mate, “Saint of Circumstance” and the players plowed through what would be a six-song, pre-“Drumz” segment.

The concert ultimately ran more than three hours, split into sets of 75 and 110 minutes, respectively. It jumped out of the gate 15 minutes after the scheduled 7 p.m. start time with Mayer singing a traditional rendition of “Cold Rain and Snow” and Weir stepping right up for the bouncy “Iko Iko” that followed. Hart sported ear monitors emblazoned with small Steal Your Face iconography; stuffed dancing bears were placed strategically on the stage; and a huge video screen alternated between live shots of the action and cool representations of band logos and Jerry Garcia’s beloved “Tiger” guitar to keep things interesting from a visual perspective as well as an aural one.

Set No. 1 was ultimately something akin to Dead & Company opening for itself and explored mellower fare such as “Row Jimmy” and “Tennessee Jed” – although Mayer lit a fire under the band and audience with his guitar solos on “Sugaree.” At one point, a roadie brought an acoustic guitar out for Weir; he fiddled with it, but it was balky, so “Looks Like Rain” was played on electric.

Back in the gloaming of a Midwest summer evening, Weir and Mayer split the verses on “He’s Gone” and a celebratory rendition of “Truckin’” melted into the impassioned blues of “Smokestack Lightning,” which provided Weir an opportunity to growl and Mayer another chance to snarl on six strings.

Seemingly kicked up by the delirious cacophony occurring on stage, the winds began to whip when Burbridge joined Hart and Kreutzmann behind the drums for a raucous percussion interlude that benefited greatly from his presence. The fairly howling winds made “All Along the Watchtower” the ideal choice for returning from “Space” and when the band closed the main set with an uptempo rendition of “Going Down the Road Feeling Bad,” on which Weir, Mayer & Burbridge traded verses, all but the most jaded Deadheads must have been feeling pretty good about what Dead & Company are turning out to be.