With her shaved head, dramatic lashes and regal presence, Laura Mvula commanded attention before she’d even sung a note last spring on Later… with Jools Holland, the British music showcase also broadcast in the U.S. But her soulful alto sealed the deal, as it does on Sing to the Moon, which emerged as one of 2013’s most captivating debuts.

Hard to believe that barely three years ago, Mvula was a receptionist for the Birmingham Symphony Orchestra, sending out demos of her songs as a classically trained composer shy of the vocal spotlight. Her universe shifted when producer Steve Brown (Elton John, the Cult) responded to that music. Mvula recorded Sing to the Moon, which shot to acclaim, vying for awards like the prestigious Mercury Prize for U.K. album of the year.

“I haven’t really had much time to process all the exciting things that have happened,” Mvula, 27, says from London. “I’m a big dreamer. I’ve always been that way. The surprise is that I never expected it to be a reality.”

Those dreams came true under the celestial tug of Sing to the Moon, where Mvula multitracked her rich vocals across strings and bell-like percussion to forge a sound unique to the pop landscape. “The voice is something within that bigger picture,” says the composition graduate of Birmingham Conservatoire. “The emphasis on being a singer is off-point to me, and it can be a distraction in our X Factor generation… What’s more important is the music, what you’re doing with it.”

Grounded in piano and violin in a musical family weaned on jazz and gospel (younger siblings James and Dionne now play cello and violin in her touring band), she preferred singing in a chorus to taking the vocal lead. “I just got really attached to voices and, particularly, harmony,” says Mvula, who was inspired by the English R&B girl group Eternal as well as Nina Simone. She joined her aunt Carol Pemberton’s a cappella ensemble Black Voices and later directed a community gospel choir.

Mvula’s penchant for harmony and texture color her songs, which were incubated in sketches on her laptop and fleshed out with strings, horns and cascading overdubs of her vocals in the studio. “It was much more experimental,” she says, “but it was always this core sound that was making its presence known through the process, like ‘This is me.’”

Sing to the Moon magnifies ethereal ballads, intricately arranged yet often minimalist in tone. Nonetheless, its undercurrent of martial drums and orchestral percussion yields to a more driving beat on “Green Garden” and the album’s affirmative peak, “That’s Alright,” about finding validity, respect and, ultimately, freedom for yourself.

“It’s a song that comes out of exhaustion from being on a journey, an endless driving for affirmation from others,” she says. “It seemed like a dead-end road—just hard, especially in putting a record out.”

Now, with the success of Sing to the Moon, Mvula has realized another ambition: She recently re-recorded the album with Holland’s Metropole Orchestra at Abbey Road Studios. “[It was] just hearing it almost as it was imagined to be,” she says of the recording, slated for a late spring release. “If you consider [that the original album] was like a nucleus, this is it in real form, with everything climaxed.”

Mvula says she hopes to eventually tour with an orchestra. But for now, she’s returning to the U.S. for a tour that includes an April 7 date at the Sinclair, fronting her sextet that includes classical harp, drums, upright bass, cello and violin, with vocal harmonies all around.

She’s thankful to be touring with her siblings. “They just keep me sane and focused and not taking life too seriously,” Mvula says. And they help temper her stage fright (“Another thing that I had to learn to manage, and I’m still learning”), as do her receptive fans.

“I remember feeling this was a very private, personal niche thing,” she says of her album. “Music becomes personal to people very quickly if they connect to it—and that’s been incredible to watch.”

Laura Mvula plays the Sinclair on April 7.