The Vineyard Sound is a force. Draped from head-to-toe in pastels with their fingers always at the ready for snapping and their pitch perfectly in tune, it’s hard to describe the Island’s premier 10-man summer a capella group otherwise. Their exuberance transmits an unparalleled contact high. Just try feeling badly around these guys.

“What we really try to do is embody that element,” said Mark Thurner, a recent Skidmore graduate and returning member of the Sound. “If we’re selling anything, it’s sort of the spirit of the summer, the spirit of having fun and enjoying yourself, and just sort of letting the problems of your life dissipate and focusing on something that’s a little more easygoing.”

Just try not to smile when these guys start singing — it's impossible. — Jeanna Shepard

The group travels around the Island leaving a trail of summer spirit in their wake. They have weekly gigs in Oak Bluffs, Chilmark and Edgartown. On nights when they don’t have public performances, they’re available for private hire. They also do impromptu street performances.

Their shows are packed with smooth doo-wop, lively banter and impeccable choreography. At a standing-room only Monday night concert at the Parish House of the United Methodist Church in Oak Bluffs they performed renditions of Stand by Me, Oh Darling, Stacy’s Mom and Beyond the Sea, all accompanied by deft and hilarious pantomime.

The following evening at the Chilmark Community Church, they sang classics like Tupelo Honey, Vincent and Walking in Memphis with unflagging energy. The group is nothing if not consistent, with a sound that is rich and full. They hone their act with a rigorous daily rehearsal schedule, but also make time for fun.

“It’s important for us to do that, because the work that we do to sound as good as we do and to be easygoing on stage is very difficult and requires a lot of higher thought, preparation and rehearsal,” Mr. Thurner said.

In between rehearsals and concerts, they go to the beach, observe made-up holidays (short tie day is one) and play with nerf guns on an obstacle course they constructed outside their up-Island rental home.

Soul to soul, brother to brother, a capella, sounds good to me. — Jeanna Shepard

Connor Bennion, who is in his third summer with the Sound, said, “At first glance if someone says hey, I’m part of a group of 10 college-aged guys, we’re going to rent a house, most landlords won’t give it a second look.” The reputation of the group helps, though, and sometimes fans will pull strings.

If 10 guys living in one house sounds like a recipe for squalor, think again.

“I have a system of plans implemented, contingencies, you might call them, in order to ensure that our amazing landlord does not walk into the house and start crying,” Mr. Thurner said.

The group divvies up responsibilities according to a chore chart. They each take care of food for themselves—they say everybody in the group has some sort of dietary restriction. By their reports, pasta and frozen pizza are mainstays.

Above the sink there are rules listed to ensure compliance with a dishwashing protocol. They also follow a strict no-shoes policy in the house.

Reunion show takes place at the Tabernacle on July 29. — Jeanna Shepard

Members of the Sound said on a cleanliness scale of one to 10, with 10 being spotless, the house is a solid eight.

“The secret is from the beginning to create a culture of cleanliness, and a culture where people hold each other accountable for that,” Mr. Thurner said.

Because they spend virtually all their time together, group culture is very important to the guys. Business Manager Gavin Morgan described key traits as being optimistic, uplifting and hardworking.

The Sound’s selection process aims at maintaining this culture. Prospective members do not audition. The Sound operates more like a secret society, with prospective members receiving invitations to join based on peer recommendations.

The group started in 1992 with 10 men from Wesleyan, Skidmore and Connecticut College who simply loved to sing and wanted to do so over the summer on Martha’s Vineyard. It is now a 501(c)(3) non-profit. Each performer is considered a contract artist; they are paid out of the donations they receive at their shows and the fees they charge for private gigs.

The group has kept to its collegiate roots, though. The recommendation process means the core contingent of the current group represents the three foundational schools still.

“I’d be lying if I said the Vineyard Sound didn’t have a little bit of a role in my college application process,” Mr. Bennion, a rising senior at Wesleyan University who knew of the group from his brother, said.

Key Vineyard Sound traits: optimistic, uplifting, and hardworking. — Jeanan Shepard

The group occasionally branches out to other schools. This year there are additions from the University of Connecticut and Plymouth State University. They are not considering extending invitations to women, however.

“We as the Vineyard Sound present a certain nostalgic feel to fans... a lot of people will be like, oh man, it feels like the ’50s,” Mr. Bennion said. “That’s, I think, what people in our audience expect to see.”

“The group’s been around for 25 years now and that’s currently the tradition,” Mr. Thurner added.

Their old-school approach is also apparent when they discuss the appeal of a capella music. “It’s a sense of purity, because the moment that you bring instruments in, it immediately is redefining the balance of the sound,” Mr. Thurner said.

Mr. Morgan agreed: “That purity of the human voice is also just a way to connect with other humans.”

Their classic Good Old A Capella captures it well: “I’m singing a soul to soul / brother to brother / a capella / sounds good to me.”

In commemoration of their 25-year anniversary, the Vineyard Sound will have a week of special events leading up to a reunion show on the Tabernacle on July 29. For a full listing of events, visit vineyardsound.org.