“It is the joy of my life,” Phil Lesh explains with equal measures of enthusiasm and reverence, as he reflects on his recent spate of performances with sons Grahame and Brian, who are both in their twenties.

While the bassist remains energized by his ongoing efforts “to move minds” while onstage with Furthur, Phil Lesh & Friends and a variety of ensembles that he has assembled at his Terrapin Crossroads venue in San Rafael, Calif., he takes particular pride in his guest appearances with the aptly named Terrapin Family Band.

The group began to coalesce in early 2012 with the launch of Lesh’s restaurant and performance venue. “It started with the bar shows—we did the soft opening bar shows before the grand opening in March,” Grahame recalls. “That was four nights and a full rock band with all sorts of guests: Bobby [Weir], Jackie Greene, Tim and Nicki Bluhm and Deren Ney, and the Railroad Earth guys came…It was just a whole crazy weekend. Even after the big 12-show run to open the whole thing, there were the Rambles and other shows. While they were rehearsing, my dad and whoever else was in town found that they enjoyed just going into the bar afterward and playing some music. There are all kinds of great experiences with that. The power went out one time, so they played acoustic by candlelight.”

While they serve as the venue’s house band, the group, which is led by Grahame and Brian, has expanded their ambit, making their East Coast debut this past June with three nights at Sullivan Hall, followed by an Infinity Yacht Cruise (and a return engagement in August). Family Band regulars Ross James, Scott Padden and Alex Koford joined the Lesh brothers at these shows, while their founding father beamed as he performed alongside them. Whenever the elder Lesh joins the core lineup, he adds richness and nuance to the group’s sound not only through his bass but also through his voice—in part because the Family Band is, after all, a family band. The elder Lesh muses on the nature of these vocal harmonies.

“There was no way to anticipate the exact nature of the color of the tone but I had hoped that it would sound really cool, which it did,” he says. “I think it’s largely genetic in that both parents and children inherit similar vocal structures. Also the connection that we have as family makes it easier to sing in tune and harmony. When the voices blend properly at the right dynamic level and everything’s in tune, the overtones mesh in a way that doesn’t happen with non-blood relatives—there’s just a super-creamy smooth or even sometimes a buzzy quality to the tone of the mixed voices. It’s absolutely unique and it’s unique to every family. The Everly Brothers don’t sound the same as the Wilsons from The Beach Boys gang. It’s almost like a signature to that genetic structure.”

The Lesh family singers have only performed in public with regularity since Brian graduated from Princeton in 2012. (Grahame received his bachelor’s degree from Stanford three years earlier.) However, Phil explains that they previously had made a few token appearances, including one in a slightly surprising setting. “I sang with Grahame a few times when he was in school playing at school functions and the three of us sang together at our mountain vacation spot. They have a talent show, so we sang together several times at one of those, and that’s when it first struck me that we really had a neat blend.”

Looking back to the brothers’ youth, one might wonder if their musical tastes ever ran so far afield of their father to test his patience. Teenagers can recoil from their parents’ interests and inclinations, whether consciously or unconsciously. However, this seems like a particularly challenging hurdle when, as Grahame explains, your father is drawn to “really complicated classical music, the really weird twentieth century stuff,” along with equally “complicated and interesting rock music.” As it turns out, Lesh proved to be an open-minded, supportive father, although he acknowledges one moment when he expressed frustration with the sounds that reverberated from his elder son’s bedroom.

“Grahame was and is a heavy metal fan. At one point, he was playing it really loud and I walked into his room and said, ‘You know, Grahame, that’s Godawful crap. You know that, don’t you?’ And he looked at me and said, ‘Well, dad, it may seem that way to the untrained ear…’” Grahame’s dad pauses and laughs at the memory.

He is, by turn, serious and stirred as he considers the current state of their evolution as musicians. “It’s absolutely a joy for me to listen to them play, either one or both together,” he says. “They have developed so far in the last year and a half and it’s because they play together very frequently, a few days a week and with their own bands a lot. It’s the only way you can really develop and I’m so pleased to see that happen and that they want to do that.” (Beyond their weekly gig with the Terrapin Family Band, Grahame performs with Midnight North while Brian is a member of American Jubilee.)

Indeed, Terrapin Crossroads is a direct outgrowth of an experience that Lesh shared with his sons. Back in August 2010, the three performed at one of Levon Helm’s famed Rambles in Woodstock, N.Y. This prompted Phil and his wife Jill to embark on a mission to open their own home venue, which is something The Grateful Dead had first discussed in 1968. Looking back to that initial Ramble, Grahame reflects, “I do remember that after the show, we follow Larry Campbell across the floor, open the door and we go into Levon’s kitchen. It’s just his house, and everyone’s hanging out in his kitchen and you can just see a light bulb go off in both my parents’ heads, ‘Oh, wow. We kind of want this.’ Because my dad likes playing all the time, but touring is always difficult and so they just sort of got that idea.”

Although Grahame and Brian didn’t realize it initially, part of their parents’ intention was to make Terrapin Crossroads a true family affair.

Their dad now relates, “We hoped that they would want to be involved. In a way, we built it for them so that they could if they wanted to, but at that time, the guys weren’t really sure how far they wanted to go with music. But luckily, they did want to and now we’re able to sing and play together frequently.”

Grahame acknowledges, “I figured we’d be involved because we really enjoyed playing together and my mom loves watching us. How much, I didn’t know. But then, for the opening run, my mom books me for 12 nights. I was able to do it despite the day job, and since then, it’s been all good.”

Meanwhile, Phil Lesh is by no means a figurehead or absentee owner. Lesh, who professes a particular fondness for the venue’s beet carpaccio, explains, “We go down there quite often. It’s a restaurant and you really have to be there. And I’m kind of the host so I go down there regularly. I particularly like to hang on Tuesdays and Wednesdays to hear the boys play.”

A good portion of his hanging also takes place with a bass strapped around his neck. Lesh has joined free bar shows, ticketed events in the Grate Room and even surprise outdoor performances on the patio. Numerous appearances have been with his sons, whether he’s sitting-in with the Family Band or joining them in other contexts, such as the rollicking, playful Rambles that are a nod to the late Helm (and named with his blessing). Beyond that, Terrapin Crossroads has seen Phil perform with Furthur, in multiple incarnations of Phil Lesh & Friends, and in Telstar shows—evenings devoted to freeform, space-inspired instrumental music, which are sometimes listed on the Crossroads calendar with the tag “Keeping it Weird.”

The Telstar description could be one of Phil’s mantras. Even as he takes deep pleasure in performing with this sons—all the more so within the comfortable confines of the restaurant/performance space that he has built with his family—he maintains the animating principle that propelled his efforts with the Grateful Dead. Lesh avows that has never wavered in his ongoing commitment, whatever the musical context, “to open up the pipeline for that eternal music.”