The Vespers are one of those lucky young bands who are becoming a word of mouth sensation though they’ve only quietly self-released one record. With two sisters on lead vocals and two brothers filling out the sound, the foursome are distinguished by an arsenal of instruments and the kind of harmony only siblings can create. They have toured from Boston to Austin, hitting everything from festivals to college campuses in between. On The Fourth Wall, out April 3rd, they create infectious folk-pop with both the buoyancy of youth and deeper spiritual themes.

The lead vocalists Callie (21) and Phoebe Cryar (19) were brought up in a musical family in Nashville, honing their gifts as young kids singing background vocals on Music Row. While their pure harmonies are described as “ghostly and haunting” and “honey sweet,” they both have expansive characteristics to their vocal and instrumental abilities. It was a chance meeting at a campfire jam that brought the sisters an earthy grounding in brothers Bruno (20) and Taylor Jones (22), who were drawn to gritty southern rock and the depth of their father’s record collection that included soul music from the likes of Stevie Wonder.

Everyone in the band contributes to the songwriting, and the only outside track is influential bluesman Son House’s “Grinnin In Your Face,” but the most prolific writer is Phoebe who contributed to nearly every song, including “Better Now”, the record’s opening track. “I came up with the melody and Bruno pounced on it, writing the bridge that completed the song,” she shares. “It was drawn from the biblical story about the man blind from birth who was healed, and no matter how much he implored – they wouldn’t believe it was possible.”

“We all grew up listening to a little bit of everything, but roots music didn’t come in until more recently,” says Bruno. “Folk and roots music tend to draw from spiritual themes. We don’t run away from our faith when writing, because that’s where our hearts are planted.” On “Lawdy,” the song starts out sounding like a swampy old mountain tune before growing into a full-bodied Sunday morning spiritual. “We were originally playing it really fast with drums,” says Callie, “but we slowed it down to be more bluesy. I wanted to hear that sound of Johnny Cash’s “God’s Gonna Cut You Down.”

The Vespers also offer a full share of effervescent pop songs like “Will You Love Me” and “Flower Flower.” Callie and Bruno wrote the latter when he said he needed a “summertime jam.” Callie hummed a melody, and the tune quickly sprung up on the banjo, ukulele, drums and bass. “Most of our songs come about really organically like that, without planning to write. It just happens and we try to let it flow,” says Bruno.

“Got No Friends” is a tip of the hat to the bluegrass genre. “We cut the first half live around one microphone, which was a first for us,” says Taylor. “That song was written right after the Nashville flood, and right as I learned to play mandolin after our family business flooded. Our world was really shook up after that May (2010). The flood eventually inspired us to quit our other day jobs, school, and pursue music full time, on a leap of faith.”

Most of the songs have the energy of a live show because the band polished them on the road, where they also came up with the album title. The fourth wall, in theatre terms, is the invisible wall between the audience and performers. “Our music reflects that. We decided to go on tour shortly after we joined forces and we really learned what our band was all about while playing to the people at our early shows. It shaped us and that’s how we really became ‘The Vespers.’ It’s all about connecting with people and breaking down that invisible wall.”