We laugh when opera diva Maria Callas says, "This isn't about me" in "Master Class." Of course it's about her. But it's about so much more.

It's about the value of art in society and the price artists pay to give us their genius.

Terrence McNally's play, which won the 1996 Tony Award, is loosely based on a series of 12 master classes that Callas gave at the Juilliard School in 1971. It was late in her career (she died in 1977), her voice was deteriorating and she hadn't performed in some time. The American-born Greek soprano was one of the most renowned opera singers of the 20th century. Joan Sutherland, Beverly Sills, Montserrat Caballé – she outshone them all, at least in her mind.

"How can you have rivals when no one else can do what you do?" she asks.

And so, no longer singing but still tempestuous and tortured, she shared her knowledge with young singers.

Janis Stevens – fiery, confident, intense yet regal – stars as "Il Divina (the divine one)" in the extraordinary Capital Stage production that opened Friday. "Master Class" is not a one-woman show, but it might as well be. It's essentially a monologue interrupted by an interval and a series of cameos in which three aspiring singers take turns being alternately encouraged and discouraged by Callas. Even when she is not speaking, Stevens – as Callas – commands the attention. Director Jonathan Williams (whose pacing is precise throughout) and lighting designer Ron Madonia ensure that the diva, whether sitting or standing in the background, listening intently or lost in reverie, always is present. The eye can no more ignore her than the ear could ignore the voice of Callas.

The singers have names: Sophie (portrayed by Wendolyn Cooper) is the first soprano, a student with a pleasant but unremarkable voice; Sharon (Laura Pyper) is the second soprano, who flees in terror upon her first encounter with Callas but returns later to confront her; and Tony (Ian Cullity) is the tenor, the only singer with the confidence to match Callas' – and a swagger that nearly makes her swoon. His singing of "Recondita Armonia," the painter's aria from "Tosca," nearly brings her to tears. Manny, the accompanist who provides piano support to these performers, is well-played by Michael Wiles. Andrew J. Perez plays the thankless Stagehand, whose every breath seems a disappointment to the diva.

As she ostensibly conducts this class for singers, Callas reveals through instruction and interior monologue, her life story. Poor, fat, insecure, she fought to become the creation that was "Il Divina."

Her monologues (seductively lit by Madonia and enhanced by sound engineer Ed Lee's fine work) recall her first marriage to an older man, her controversial love affair with Aristotle Onassis, and her final performance at La Scala.

In the end, McNally asserts, the truth of Callas' existence, as of every great artist's, is this: "We give the audience everything and when it's gone … we're the ones who end up empty."

There is only one word for this "Master Class": Brava!

© Copyright The Sacramento Bee. All rights reserved.

Call The Bee's Jim Carnes, (916) 321-1130.

• Read more articles by Jim Carnes