Ronnie McCoury sounded apologetic as he ended a recent interview with GO! Magazine.

He didn’t have much reason to be contrite. The mandolinist, vocalist and son of bluegrass legend Del McCoury had been on the phone for a half-hour discussing The Travelin’ McCourys’ upcoming first studio album, the band’s current tour and his and his brother Rob’s early years playing with their dad on the road.

“I hate to cut you off, but I hear these guys — let me play a little for you here. Hang on a second, if you can hear this,” Ronnie said from Louisville, Kentucky, as a tinny, slightly muffled bluegrass jam drifted over the line. And then he laughed — a low, rumbling chuckle that punctuated almost every previous statement he made.

Ronnie’s affable demeanor — part patient music historian, part good-natured goofball — is no accident given the bluegrass music world he grew up in. He’s been touring since age 14, when he joined his dad’s eponymous band in 1981. Ronnie admitted to being “scared to death” in those early years, but he found plenty of support from the musicians with whom he shared stages.

“I would just kind of stand right close to the side onstage,” he said. “But it’s such a wonderfully welcoming family of musicians, bluegrass musicians are. No matter where you played — and you’ve gotta remember that it’s not like we’re playing a rock coliseum or anything; we were playing smaller festivals and one-day shows and things like that. We grew up in the state of Pennsylvania, and my dad mainly played on the East Coast, so he had already done a lot of traveling before I came along. It was just a welcoming family of people, and they encourage you so much.”

Now aged 50 and 46, respectively, Ronnie and banjoist/vocalist Rob are continuing that welcoming tradition with The Travelin’ McCourys, an offshoot of the Del McCoury Band that also features that group’s bassist, Alan Bartram, and fiddler, Jason Carter, along with guitarist Cody Kilby (known for playing with Ricky Skaggs). The band, which performs at Volcanic Theatre Pub on Thursday with The T Sisters, formed in 2009 at the encouragement of Del and has spent nearly a decade straddling the line between traditional bluegrass and the jam-oriented, progressive sounds typified by bands such as Greensky Bluegrass or Yonder Mountain String Band.

That dichotomy is reflected in The Travelin’ McCourys’ festival-heavy touring schedule, as well as its annual Grateful Ball live bluegrass tributes to The Grateful Dead. And it’s sure to come up on the band’s upcoming debut album, which will be released sometime in the spring, Ronnie said. The record was preceded by three singles released in 2016 and 2017, including two Grateful Dead covers and a string-band version of British songwriter Passenger’s 2012 indie-pop hit “Let Her Go,” that may or may not be on the full-length.

“I have a daughter who’s 14, and it was probably a year or two ago, but she was playing this song (‘Let Her Go’) in the house, and she was into it, so I heard it a lot,” Ronnie said. “I thought, you know, that’s just a good song. I’ve always felt and my dad just kind of handed down that a good song is a good song and can be done any way. So I thought, I’m gonna see if we can do it our way. I gotta say, we did a record with Keller Williams (2012’s ‘Pick’). He’s really well known to cover people and do it his own way, and I give him some credit for that.”

The singles were originally meant to be the start of a monthly series. “That’s a plan that gets handed to me from the higher-ups in our organization, and then it fizzled out, as they say,” Ronnie said with another laugh.

“We did about 70 shows with The Travelin’ McCourys last year and almost 70 with my dad,” Ronnie said. “My father’s also — he’s very active; we play all the time still. It’s a balancing act, you know. Along with that, my dad is also a Grand Ole Opry member. … We do a lot of gigging; that’s what I’m getting at. So it’s been hard to pin everybody down, but in the last couple of weeks, starting — we actually played with my dad on a run, we called it the Get on the Bus tour. … As soon as we got back from that, we started a record with him that just got finished last week. So we’ve done two records in the last month or so, and finally getting it all together for the folks.”

Thanks to their father, Ronnie and Rob grew up surrounded by bluegrass musicians from the first wave of the genre — Bill Monroe (one of Del’s early gigs was in Monroe’s band in the ’60s), Earl Skruggs, the Osborne Brothers and Jimmy Martin, among many others. Just as Del took his sons under his musical wing, the McCoury brothers are ushering a third generation into the family business — Ronnie’s eldest son, Evan, has guested with his father onstage.

Ronnie said he understands the bluegrass purists in the band’s audience. However, many of the genre’s heavyweights, his father included, have been at the forefront of pushing the style’s boundaries over the years, he pointed out.

“Fortunately, I’ve been around all of them and heard them, and I can appreciate what a lot of people say about that — there is a beauty to a three-minute song,” Ronnie said. “But it’s also pretty interesting to see how the people that have taken this music to different places — it kind of started with John Hartford as a father of newgrass, and then the New Grass Revival as the band that changed a lot of it, up to now: Greensky or the Dusters or whoever. These guys are using the instruments and taking it to a different place. I’m kind of glad to have my foot in both, you know.”