Medford native Eric McDonald, 31, has become one of the more prolific performers in the Boston and New England folk/traditional music scene. Now based in Portland, Me., McDonald – an accomplished guitarist, mandolinist and vocalist – has played in a duo with Scottish/Cape Breton-style fiddler Katie McNally and as a member of contra dance trio Matching Orange, among many other collaborations, and more recently in Irish/Celtic trio Daymark and the long-running Scottish band Cantrip. He’ll be appearing with the latter group on Aug. 29 at 7:30 p.m. as part of The Burren’s Backroom series.

Earlier this year, Cantrip – whose members also include Jon Bews (fiddle, vocals) and Dan Houghton (pipes, flute, whistle, guitar, bouzouki, vocals) – made a live recording slated for release shortly. McDonald discussed his musical activities – past, present and future – with Sean Smith of the Boston Irish Reporter.

Q. What were some of the key formative experiences for you in Boston that put you on the road to playing Celtic and traditional folk music?
A. Gosh, there were a lot of them. I really got the music bug going to shows at Club Passim in Cambridge. Historically, Passim is a hub for singer-songwriters and still is, but when I started going it was during a natural progression that brought a lot more Celtic and traditional music through the doors, so I was exposed to a lot of fiddle. It was amazing the sheer number of amazing musicians I had the opportunity to see.
Boston’s musical community is very welcoming, and when I showed an interest it was easy to find a way in. Meeting and playing with all these musicians I was watching on stage was incredibly powerful, and really set me on the path. I also sang in the chorus for Cambridge Revels, and that did a lot to teach me about how traditional music can and should be connected with community. Later on I studied at the Berklee College of Music, and of course that was pretty important as well.

Q. What is it about the Boston area that makes it such a good place for folk music, especially the Celtic/Irish/trad?
A. To be completely honest, I’m not entirely sure what makes Boston so vibrant compared to other places. I’m certain that our rich immigrant history plays a major role. I think also being the biggest city in New England probably helps. There is a ton of musical heritage in these six states, and a lot of it manifests here. We also have lots of resources that draw musicians of all stripes, such as Berklee, Passim, programs like Gaelic Roots and many others. Not every place has things like that.

Q. Cantrip goes back two decades, to the 1990s Edinburgh folk music scene. So how and when did you get involved with them? What was it that drew you to their music, and has kept you with the band?
A. Yeah, those guys are old. The original four met in university, but when our piper Dan moved back to the US it put pressure on the band and eventually two members moved on. Dan and Jon, our fiddler, were the originators and the crux of the group so they kept it alive by hiring various rhythm players to sub in. I was one of those players.

It was actually the weekend after Hurricane Irene, back in 2011, when I first joined up with them: They had a gig in Vermont and the guitarist they had on board was stranded in the Catskills, so I got the call three days before the gig. From the moment we sat down to play, though, we could tell it was a natural fit. I think that carried over past the music as well. We were fast friends and I signed on quick.
We’re now great friends, and we all feel the band has been reborn better than ever. As far as what draws me to the music, besides Dan and Jon both being absolutely monster players, I find them to be very authentic musicians. I don’t think we try too hard to be anything we’re not, and the sound that comes out is very raw and energetic. Playing live is like food for us, and we all click on stage in a way that we don’t otherwise. That’s one of the reasons we’re very excited about this live album. It’s an open dialogue that lets us all be ourselves and works surprisingly well in the end. It’s really just a privilege and a joy to be a part of this group with these lads.

Q. Given your busy calendar, and the fact that Jon is living in Scotland, how challenging has it been to be able to work together on Cantrip material and to line up tours and gigs?
A. It’s tough to be intercontinental. We all have other projects to round out our schedules. There are a lot of kids in the picture as well. But we have a few different tours that we do every year and we look forward to them like vacations. We have a lot of places that we play where people come to see us year after year, and that has really helped make it work.

In terms of material and rehearsals, it feels easy because we’re all such good friends, and the music just comes. So it’s never really been a question as to whether or not we’re going to make the time. We just do it whenever we can, and we’ve never been short material. It’s built a really solid foundation for us. The last couple of years, we’ve been turning up the touring and trying to go to new places. We expect that to continue. The logistics are tough, but they’re worth it.

Q. You put out a solo album last year, and Daymark recently released an EP. What are some other recent, ongoing or upcoming projects on your slate?
A. One of my major touring projects is a duo with Washington-based fiddler Ryan McKasson. We put out an album last year called “Harbour,” and we got to have Jeremiah McLane play on it. I’m loving that project, and we’re starting work on our second album for next year. Daymark just released the EP, but we’re already hard at work on our first full-length album. After releasing this live album, Cantrip is doing another studio album in the spring.
All of these acts are on the road regularly. I’ve also been doing some touring with an amazing band called The Outside Track, and I’ll be back in the van with them this winter to help promote their upcoming album. This is what is keeping me busy, and all my other ideas and projects will be kept at bay until these are completed.