Thurs. March 18 

Club Passim has not always been called Club Passim, but the spot on Palmer street in Harvard Square has been a go-to place for folkies for, oh, five decades. For the past fifth of those storied 50 years, local singer/songwriter Alastair Moock has been inviting his friends to Passim for a free-form song swap and mutual admiration society he calls "Pastures of Plenty." On Thursday March 18, PoP will celebrate its 10th anniversary with a special show featuring Moock, along with featured guests Jeremy Lyons, Kellen Zakula and Sean Staples. "Roots music was always synonymous with community for me," Moock explains. "That was the main attraction. The first folk concerts I saw were collaborative shows by Pete Seeger and Arlo Guthrie where everyone participated in everything.You didn't just sit and watch; you were part of it. It was a wholly different experience than I'd had at other shows. When I started playing, I tried to make my own shows that way too. I still do. In addition to being communal and collaborative, the Patures shows are also greatly improvised which adds to the energy and flow between and among the performers and audience members.

"Basically, we [are] creating something new each time on stage," Moock says. "They used to call that a hootenanny." Surrounding himself with musical friends (many of whom Moock modestly admits may be "better" than he is, though that is debatable), Moock has put together what has become one of the most anticipated and appreciated musical opportunities for players and fans alike.

"I started Pastures because I wanted to have an opportunity to hang out and collaborate with other songwriters," Moock says. "It was something I felt was missing on the Boston folk scene. It was also because I love Roots music and I wanted to expand its audience by bringing it to new people."

Though Moock is a roots fan at heart, his albums and performances always involve a healthy and edifying mix of Olde Tyme and modern songs that range in topics from civil rights to the right to a good latte. In bringing together such diversely talented performers, PoP has helped Moock and his guests expand all of their repertoires. Among past PoP performers have been Bill Morrissey, Lori McKenna, Ronnie Earl, Kris Delmhorst, Catie Curtis, Barrence Whitfield, Sarah Borges, Dennis Brennan, Rani Arbo, and The Silver Leaf Gospel Singers, to name just a few. No matter who drops in, however, PoP always delivers on its tacit promise to be lively, fresh, and fun.

"I try really hard to get a good mix of performers," Moock says, "because part of the Pastures mission is to bring different audiences and musicians together."

"We've got bi-monthly shows booked for the rest of the year," Moock says, whetting the appetites of Pastures faithful. We'll be bringing back some of our old favorites along with a lot of new blood."

Speaking of new blood, it was not long ago that Moock welcomed his first offspring into the world. "I had twin daughters three years ago," Moock says. "Or my wife did, but I helped. That's changed life pretty completely. I've cut way down on my touring. But that's actually given me more time to focus on stuff around here, like Pastures."

In addition to changing his schedule and his sense of sanity, the birth of his daughters pushed Moock into another booming business- that of children's music. (See: Dan Zanes.) His recently released "A Cow Says Moock," features a collection of classics and original compositions that work well for kids and parents alike. And like PoP, the album also features some of Moock's most talented friends, including Jennifer Kimball, Maria Sangiolo, and Swinging Steak Jamie Walker.

"I'm doing a bunch of family shows," Mocck says, "which I'm enjoying so much. Most of our close friends have little kids at this point, and it's great to be able to offer something musically to them and their kids. I'm even starting to do some collaborative shows on the kids front. Maybe at some point, we'll up with a Pastures Jr. series. Who knows? I'd like that."

In the meantime, however, Moock is happy to be performing with and for his peers. The music, he says, keeps him young and keeps others coming back for more. "When I started doing these, I was the new kid in Boston," Moock recalls. "Now I'm the old man, and there's a whole new crop of young players to discover. So much amazing talent in Boston, there’s never a shortage to bring in to this series."PoP starts at 8. Tickets are $16.

(Contributed by Matt Robinson.)

47 Palmer St., Cambridge 617-492-7679, www.clubpassim.org.