Richard Baker knows Patricia O’Neill will cringe when he says it, but it’s the best way he knows to describe Maria Callas to those unfamiliar with opera.

“I tell them that she was the Michael Jackson of the opera world,” he says. “She commanded that kind of awe and respect.”

Baker and O’Neill are co-directing Theatre Baton Rouge’s production of Terrance McNally’s drama “Master Class,” which explores Callas’ life in the setting of one of her legendary Juilliard master classes.

Theatre Baton Rouge is partnering with the LSU School of Music and LSU Opera in presenting this show, which opens Friday in the LSU School of Music Recital Hall.

“This is our way of bringing Theatre Baton Rouge to the community,” Baker says. “Maybe if they visit us here, they’ll come visit us again at our home on Florida Boulevard.”

McNally’s story is a fictional look at Callas based on real events in her life. Callas was an American-born Greek soprano whose musical and dramatic talents earned her the title “La Divina,” or “the divine.” Or “diva.”

“Yet she had two personas,” Baker says. “When she was on the stage, she was La Divina, but she was very reserved when she was off stage.”

“She was an introvert,” O’Neill adds. “Introverts tend to process things inside and are deeply sensitive. She wasn’t known for big gestures. Instead, she had the ability to go deep within herself, digging deep within her soul to find the character she was portraying. She was subtle but powerful, and it’s amazing to watch her perform.”

Though Callas died at age 53 in 1977, the Internet has preserved her performances on YouTube and other sites. The bulk of Callas’ career covered only a decade, yet it was enough time to establish her legend.

Callas was born in 1923 to an overbearing mother in New York. After her parents’ separation, she eventually moved to Greece with her mother and sisters. She was known for her impressive range. She also had an unusual beauty and, according to legend, temperamental behavior.

“But if you look at the recordings of the master classes she conducted at Juilliard, she is very subdued,” O’Neill says. “There are a lot of myths that surround her. She was enigmatic and archetype.”

McNally puts some of the Callas legends to work in “Master Class,” which has Callas, played by Sandra Moon, teaching three students. There are times when she overflows with kindness and other moments when she lashes out in frustration.

“I can understand her frustration,” Moon says. “She’s trying to reach out to students who haven’t prepared for the music as she has. She cares deeply about the music, and they don’t take it seriously. I totally see where she’s coming from.”

Moon is in her second year as an assistant professor of voice at LSU. Before that, she was a full-time opera performer in Europe and the U.S. “Master Class” is her first play.

“I’ve been onstage in operas, and many have required me to recite dialogue,” she says. “But when Pat O’Neill suggested that I try out for this play, I said no. I’m not an actress. But then I started thinking about it, and the more I thought, the more I realized that it was something I wanted to do. We were both sopranos who sang opera, and I admire Maria Callas.”

Still, there are some things about Callas with which Moon can’t identify. Callas was, indeed, a superstar, the kind that drew paparazzi.

“There was someone who recognized me outside of a theater after a concert,” Moon says, “but I never had anyone chasing me.”

Callas also had a publicized affair with Greek shipping magnate Aristotle Onassis.

“She died alone,” O’Neill says. “She was living in an apartment in Paris. Her heart had been broken. There’s a picture taken of her in that apartment before her death. It shows her sadness and loneliness.”

The mix of her artistic achievement and dramatic life launched her to a stardom on the same par with the likes of Jackson. Leonard Bernstein called her “the Bible of opera.”

And Opera News wrote in 2006, “Nearly 30 years after her death, she’s still the definition of the diva as artist.”

McNally’s play leads the audience in and out of her master class, dealing with students at one moment, then chasing a memory in the next.

“And the Recital Hall is the perfect setting for this play, because this is where the master classes are taught at LSU,” O’Neill says. “It’s stark, as Maria Callas liked it — just her, the students and the music.”