Grateful Dead bassist Phil Lesh plays alongside his son, Grahame Lesh, on guitar at Thompson’s Point in Portland. Photo courtesy of Robert Ker

It’s a rare and special occasion when a member of the Grateful Dead visits Portland.

After years of relative quiet, guitarist Bob Weir performed a pair of shows at the State Theatre in 2019, and on Sunday, bassist Phil Lesh took to the stage outdoors at Thompson’s Point for a gem of a concert that included rarities, favorites, covers and inspired interpretations of material from the extended Grateful Dead catalog.

Lesh does not perform with his once and likely future bandmates in the touring juggernaut Dead & Company (which visited Foxborough, Massachusetts, on July 2); instead, he plays with a rotating mix of musicians. The names of the two bands reveal differences that might appeal to Lesh: Dead & Company implies the massive, businesslike venture of keeping the Grateful Dead brand vital, while Phil Lesh and Friends suggests an intimate jam session among loved ones.

The family vibe at Thompson’s Point suited this approach, as did the fact that Lesh was accompanied by his son, the gifted guitarist Grahame Lesh.

Throughout the concert, the younger Lesh and fellow guitarist Stu Allen played their instruments in tones similar to those of Jerry Garcia and wound their playing around each other, summoning the warm, unbound sense of euphoria and community that is so unique to Dead-associated shows that it may as well be trademarked. Aided by keyboardist Jason Crosby, singer Amy Helm and drummer Cody Dickinson, they offered an opening set of chestnuts including “Shakedown Street,” “Bird Song,” “They Love Each Other” and “Touch of Grey.”

The improvisation was tight, and the tempos were generally relaxed, which made it all the more surprising when they covered Bob Dylan’s “Shelter from the Storm” and gave Dylan’s acoustic classic a shot in the arm.

The second set was even more mellow and contemplative than the first, yet it also sparkled brightly throughout. “Rosemary,” a song that the Grateful Dead included on its 1969 album “Aoxomoxoa” but only performed in concert once, opened the set with a brief appetizer that also signaled something nifty was afoot – a hint that came to fruition when that seed blossomed into an inspired take on the beloved Grateful Dead opus “Terrapin.”

The musicians returned to more obscure fare with a cover of Dead lyricist Robert Hunter’s “Jack O’Roses” (a song from the Terrapin Station Suite that was never played by the Dead) and then returned again to populist fare with “Scarlet Begonias,” a song that has long been a superb showcase for Lesh’s creativity.

Rather than give way to “Fire on the Mountain,” the frequent cohort of “Scarlet Begonias,” the band dissolved into a long, epic version of “Dark Star.” True to the song’s reputation, the band used its structure to embark on what was handily the most abstract and experimental improvisation of the evening. The jam unspooled in a fashion similar to free jazz, with Lesh and the two guitarists pulling apart from each other with impressionistic splatters before eventually tugging the strings back together and returning to the song proper.

They closed the show on firmer ground, including the crescendos of “Morning Dew,” the uptempo “Going Down the Road Feeling Bad” and “And We Bid You Goodnight,” a song that not only helped put the show to bed but also the tour.

Lesh is 82 years old, and his phrasing on bass guitar and his overall stage presence were both remarkably spry; it’s easy to imagine he has several more years on the road ahead of him. By opting to tour with his son rather than Dead and Company, it’s also sensible to assume he’s putting a kind of spiritual succession plan in place, so that his music and legacy may live for decades, if not generations, to come. The number of children and young people enjoying the concert suggested that this will be the case.

Robert Ker is a freelance writer in Portland. He can be reached at bobzker@gmail.com.

This story was updated at 10:47 a.m. July 13 to correct information about the band Dead & Company.