One of the most talked-about young groups on the modern bluegrass scene is playing a free show this weekend (Oct. 9) at the Port Hunter in Edgartown. The Lonely Heartstring Band, a quintet of conservatory-trained string players based in the Boston area, released its debut album this summer on the famed Rounder Records label.

The band was also chosen to perform at the International Bluegrass Music Association awards ceremony in Raleigh, N.C. last month, closing the evening with their rendition of 1979 Top 40 hit The Rainbow Connection, from The Muppet Movie. The previous year, IBMA had honored the group with its Momentum Award for up and coming talent.

“They have incredible arrangements, and they’re deep,” said Rounder Records co-founder Ken Irwin in a conversation with the Gazette this week. Mr. Irwin has been scouting bluegrass, folk and roots music talent for more than 45 years, signing then-unknown artists such as Bela Fleck, Mark O’Connor, George Thorogood and Alison Krauss.

Now Mr. Irwin, and others in the tight-knit American bluegrass community, are wondering if the Lonely Heartstring Band might follow Ms. Krauss, whose albums have achieved multi-platinum status, across the borderline to mainstream commercial success.

“The songwriting is really strong, and it’s unusual,” he said. “The lead singer, George Clements, has this amazingly accessible voice which enables it to appeal to both bluegrass and folk as well as Americana and conceivably pop audiences — they definitely have a pop sensibility to some of the tunes.”

It was pop music that brought the group together, even though none of them was a pop musician, said Mr. Irwin, who first discovered Lonely Heartstring Band at a bluegrass festival in Maine a few years ago.

“A friend of theirs saw a notice at Berklee [College of Music in Boston, where four of the five band members studied] that somebody wanted a band to play all Beatles covers in bluegrass style at their wedding, so they put together the band for that show,” Mr. Irwin said. “They all really enjoyed playing together and decided to do it some more,” with Beatles tunes remaining a part of the act along with originals and other cover songs.

The original bass player was soon replaced by singer and guitarist George Clements’s twin brother, Charles, a classically-trained bassist who performs part-time with the Boston Symphony Orchestra. Charles Clements also sings, adding to the group’s versatility and delighting Mr. Irwin, a devoted fan of harmony singing.

“You can have two different duets, with the twins doing some duet parts and then Patrick [M’Gonigle, the group’s fiddler] and George doing other parts. Sometimes you’ll get those all on the same song. There are all these different layers and different textures that give it variety and make it so interesting,” Mr. Irwin said.

Banjo player Gabe Hirshfeld and mandolinist Matt Witler, both accomplished pickers, round out the Lonely Heartstring Band, which performs after dinner ends Sunday at the Port Hunter on Main street.

Restaurant general manager and talent booker Brice Contessa said he first heard about the band from another group he has booked more than once, Brother’s Rye from Woods Hole.

“I get a lot of referrals via other musicians,” said Mr. Contessa, who has been the restaurant’s sole music curator since 2013. “I always keep a little notebook in my pocket,” to jot down the names of new bands, he added.

But Mr. Contessa found it wasn’t as easy to book the Lonely Heartstring Band as one might expect of an upstart group with two members still in music school (Mr. M’Gonigle is working toward a master’s degree at the New England Conservatory of Music and Mr. Witler is in his senior year at Berklee).

“They’re very sought-after,” Mr. Contessa said. “But then we have the holiday weekend, and they had Sunday off.”

The Lonely Heartstring Band performs Oct. 9 from 10 p.m. to 11 p.m. at the Port Hunter, 55 Main street in Edgartown. For more information about the band and to listen to selected songs, visit lonelyheartstringband.com.

The print edition of the Gazette states the wrong time for the concert. The band performs at 10 p.m. on Sunday.