The first thing you should know about the Bourne family is that it is comprised of a remarkable mother and her eight adult children, all of whom possess glorious voices that, when joined in unison, create one of the most beautiful, multi-layered sounds imaginable.

When: Through Dec. 10
Where: BoHo Theatre at Theater Wit, 1229 W. Belmont
Tickets: $33 – $35
Run time: 2 hours and 10 minutes, with one intermission

I heard the Bournes sing for the first time this past summer, when they accompanied Giordano Dance Chicago as part of the Dance for Life program, and their a cappella renditions of “Total Praise” and the hymn “Softly and Tenderly” were so other-worldly it was hard to believe the singers were not on a meticulously mastered recording, or being beamed down to Earth from some higher place. In fact, when they finally emerged into the spotlight after being unseen for most of the performance, the audience at the Auditorium Theatre went wild.

More recently I reviewed a performance of BoHo Theatre’s superb production of Michael John LaChiusa’s semi-operatic musical, “Marie Christine,” a sort of Creole take on “Medea.” And while I was impressed by all the talent on stage, including Kyrie Courter, who plays the title role, there was something about the exquisite voice and presence of the actress playing Marie’s beautiful young maid, Lisette, that caught my attention. It turned out she was Katherine Bourne, the third oldest of the Bourne siblings, who is soon to graduate from Roosevelt University’s Chicago College of Performing Arts (CCPA) with a degree in musical theater (and a concentration in dance), and who serves as the Bourne Family’s musical arranger. Her role in “Marie Christine” is her first professional theater credit, although music has been part of her life for as long as she can remember.

Actress-singer Katherine Bourne. | Kevin Tanaka / For the Sun Times)

But before going any further, an introduction to the Bournes — all of whom live together in a house in the southeast side neighborhood of Riverdale — is in order.

They have no agent, and (as yet) no recordings other than a single on iTunes, although their dream is to have a record that features their self-penned songs, and, according to Katherine, “makes lots of money so we can get fully involved in community work for real.” Meanwhile, they tour to many churches and perform at special events and youth conferences throughout Illinois and surrounding states. As one of them quipped: “Yes, it’s the nine of us traveling for 12 hours in a very crowded Dodge Grand Caravan.”

At the head of the family is Lisa, the soft-spoken, artistic, clearly beloved mother of them all, who explained: “Our house has always been full of every kind of music — everything from The Carpenters, Cindy Lauper and The Judds to movie musicals and Rachmaninoff, one of my favorites. We sing everything — gospel, jazz, classical, folk, country and hip-hop. We all play a little piano and several of the kids play guitar. Ultimately, God is the reason we make music.”

Katherine Bourne (left) plays Lisette, with Kyrie Couter in the title role in the BoHo Theatre production of Michael John LaChiusa’s musical, “Marie Christine.” | Katie Stanley

“My mom got us through a lot of very chaotic times, and made the most of any situation,” said Katherine. “And she never put any of us in a box, allowing each of us to be who we were. She has never been a stage mother; actually, we still have to drag her on stage.”

The siblings — and they could not be more individualistic even if their voices blend as one — include: Elizabeth, 39, a special education high school teacher; Christina, 37, who worked at the Auditorium Theatre until last year, forged the family’s initial connection with Giordano, and is now an independent not-for-profit consultant; Katherine, 31, the actress, arranger, transcriber and more; Paul, 25, a freelance graphic designer and entrepreneur; Timothy, 23, who is studying mechanical engineering at IIT; Rebecca, 22, who is “still thinking about various possibilities”; Ehron, 19, who works as a nanny; and John, 17, in high school, and credited with creating the computer-generated electronic music they tend to listen to when driving.

“Growing up I was a very opinionated, forceful person, and even thought I might join the military or become a lawyer,” said Katherine, who names “Seven Brides for Seven Brothers” as a favorite musical and Mikhail Baryshnikov as her dance idol. “I knew I was talented, but I thought I had to tiptoe to pursue a career in the arts. Getting a Sarah Siddons Society scholarship for school was definitely a big help.”

So how did she win her role in “Marie Christine”?

“I just went to the audition and sang [the Gershwins’] ‘Summertime,’ and got a callback,” said the actress, who had played roles in such Roosevelt productions as “Hair,” “Promises, Promises” and “Cabaret.” “Then I was asked to try and sing the High C in  ‘Dansez Calinda,’ [one of her solos in ‘Marie Christine”] and I guess I nailed it.”

Working in the show has taught her “how loving the Chicago theater community can be,” but asked about how she envisions her future she confessed: “The plan is to make a plan. Our family has a ‘five year list.’ And I go back and forth about staying in Chicago or heading to New York. After taking an ‘on camera’ class at school I’m thinking about television and film. Meantime, I want to stay in the casting pool at school this spring, and focus on our senior showcase.”

Her dream roles? “I’m in love with Stephen Sondheim and would love to do ‘Sunday in the Park with George.’ But I’m also very interested in new works.”

“I’m in love with Stephen Sondheim and would love to do ‘Sunday in the Park with George.’ But I’m also very interested in new works,” says actress Katherine Bourne. | Kevin Tanaka/For the Sun Times