Maria Callas is hectoring a student about "presence."

"I'm drinking water and I have presence!" she insists.

It is a throwaway moment dramatically, but it says so much about the opera legend in "Master Class."

Callas was that rare creature who we suspect sprang into existence fully formed from the forehead of Apollo. She became an open heart in performance, daring her voice with reckless performances and leaving a bit of her soul on stage so that audiences would remember the night they saw Callas.

Actor Sally Wingert has taken the prodigious legend on her shoulders in Theater Latté Da's production of "Master Class," which playwright Terrence McNally crafted from sessions Callas held with voice students at Juilliard in the early 1970s.

"Master Class" is not a great play. It lurches in spots and occasionally goes maudlin. Don't see it for that reason. Do see it, though, for the opportunity McNally has created to study a character whose very life was a performance. Director Peter Rothstein stages this work in a recital hall — Antonello Hall at the MacPhail Center for Music — and that intimacy only makes Wingert's work more immediate and real. Callas was human, we sometimes forget, and Wingert pours out all the tools of her humanity to make the case.

As she enters the stage, Wingert's Callas knows who she is and knows she need not impress anyone with airs. She shares chatty, self-deprecating banter with the audience, comments on the lack of a cushion on her stool, displays her awkward social graces with the pianist who will help her coach these students. It is small-bore acting, realistic and never aware of itself.

Students (victims, she calls them, shouting out, "Next victim please!") enter her orbit, hoping to grab a bit of the fairy dust in the atmosphere she breathes. The leonine diva prowls, snaps, interrupts and begs these young singers to know what she knows and feel what she feels. At the least, she barks, enunciate the words and listen to the music for the journey it lays out. "It is all in the music," she says many times.

Wingert's performance is worth seeing. She becomes almost invisible in her emotional transformation (give Rothstein much credit for that) and she accomplishes this through an articulate technique: her voice is deep in the back of the throat, her gestures never wasted. The wig (Robert Dunn) and costume (Willene Mangham) provide even more cover for Wingert.

McNally chose music for this play that resonated with Callas's life and career. As the singers perform, Wingert's character recedes into herself. We see regret, age and vulnerability in Callas's inability to leap the chasm of time to past glory. We also see the impact her blunt pestering of the student has. In the case of Kira Lace Hawkins' Sophie, a transcendent performance; Kelsey Stark D'Emilio's Sharon, on the other hand, rebukes Callas' lack of generosity and slips in the dagger of truth that this old lady's salad days are long past.

Andrew Bourgoin is accompanist and music director for this production. The character is a prop but the musical underpinning is essential.

Indeed, Callas is right. She and this play — this experience — is worth our presence.

Graydon Royce • graydon.royce@startribune.com