When Two Legends Meet : Zoe Caldwell portrays diva Maria Callas in a tour de force performance. Says Caldwell: : ‘From the moment I wake up, everything is geared for Maria . . . listening to her voice.’

What becomes a legend most? Another legend, if Zoe Cald well’s current turn as the late great opera singer Maria Callas is any indication.

Portraying the famed soprano in the West Coast premiere of Terrence McNally’s “Master Class” at the Mark Taper Forum, Caldwell does Callas proud. Her performance has won critical kudos and become something of a touchstone among Los Angeles acting aficionados.

Inspired by master classes that the singer known as La Divina held in New York in the early 1970s, the play follows Callas as she takes several younger artists through their paces, meanwhile recalling her own turbulent life.

Three-time Tony winner Caldwell, 61, has had quite a journey herself, having already graced most of the key stages of the English-speaking theater and played women from Medea to Cleopatra to Lillian Hellman.

Not surprisingly, her performance here is one of those rare instances where it’s hard to tell where one artist stops and the other starts. And the synchronicity is by design.

“From the moment I wake up, everything is geared for Maria, whether it’s reading another thing that somebody’s said about her, listening to her voice, going through the script [or] making sure that I don’t have food that will be indigestible,” says Caldwell.

“A little part of you [is her] all the time,” she continues. “It’s just the way I work.”

Naturally, it helps to have a role that was written with you in mind by the successful McNally. “Terrence’s knowledge of Maria is profound,” says Caldwell. “Terrence’s knowledge of opera is profound.

“My knowledge of life is pretty profound,” she adds with a self-effacing chuckle, “but those other two areas I didn’t understand.”

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Where La Divina stops and Caldwell begins only her playwright knows for sure. But the actress offstage is assuredly not a diva.

Soft-spoken and gracious, she welcomes a visitor into a dressing room that is a sanctuary of study. Black-and-white photocopied pictures of Callas are taped all around the mirrors and a potion of herb tea, medicine for a strained voice, brews on the counter.

This is where the actress prepares. But the true preparation began long ago. “Like I do with any part--or even if I’m directing--I did an enormous amount of research,” says Caldwell.

First, she had to learn about Callas. “I really didn’t know anything about her, except that she was a diva and an extraordinary voice, but I’d never really listened to her voice,” says Caldwell. “I’m not a great opera aficionado, so I met her through what Terrence has written.”

The first surprise was finding that Callas had a soft side. “I realized that she was vulnerable,” says Caldwell. “About music, she was incredibly sophisticated. But she was also strangely naive about life.”

Caldwell’s task, as she saw it, was to convey this delicate duality onstage. “[Callas] gives the gift of allowing the audience to see her human frailties,” she says of her role. “Too often, the gods and goddesses of sport and music cover up their human frailties and don’t let the audience in.

“She lets you in on her soul, and her soul is molded by art. It’s the thing that enabled her to survive; therefore it’s an extraordinary soul. People are simply amazed that that is exposed.”

That intensity was one of her most endearing qualities, according to Caldwell: “With Maria, I respond so overwhelmingly. I adore her.”

Beyond the love, though, there’s a good deal of work that goes into Caldwell’s performance. “Every day, I read the script, top to tail, and every day I find something new,” she says.

“I [may] find that I’ve inserted some grand exclamation mark and that Terrence didn’t write it. So [I tell myself], ‘Just say it, get on with it.’ It keeps me reasonably fresh.”

The discipline apparently works.

The Times’ Laurie Winer dubbed her outing a “must-see performance by the wonderful Zoe Caldwell.” Likewise, The Times’ Martin Bernheimer called it “a dazzling extrovert performance.” And Allan Ulrich of the San Francisco Examiner hailed it as “one of the unforgettable tours de force of our day.”

But the key to Caldwell’s por trait, as well as her distinguished career, lies not only in craft. It is also a tribute to her ability to draw on all that she has experienced along the way.

Born in Australia to a plumber father and a retired dancer mother, Caldwell was inculcated with a love of the arts at an early age. She has fond memories of many family outings.

“When I was a little girl in Australia, my parents took me to everything in the theater,” she says. “We didn’t have any money, so we’d have to go in what they called the Gods, the [uppermost] balcony.”

To a child, it was actually a special place. “Up in the Gods, they had benches. And they had ‘packers’--men who went around with a short broom, padded on one end, and gently pushed whoever was on the end of the aisle, so they could get somebody else in.”

Looking back, Caldwell sees those cramped conditions as an asset. “There’s something terrific about that,” she says. “It was such a visceral thing, of sharing. That’s why I always look up high when I’m in the theater.”

After completing high school in Australia, Caldwell worked in repertory theater for several years before traveling to Stratford- Upon -Avon in England to pursue her career.

In 1965, she moved on to roles in Canada and the United States. One year later, Caldwell’s friends Jessica Tandy and Hume Cronyn arranged a date for her with Cronyn’s Canadian cousin, the Broadway producer and director Robert Whitehead.

Caldwell and Whitehead, who is 17 years her senior, married a couple of years later and she became pregnant that same year. “I got married late, and I had Sam when I was 36,” says Caldwell, whose sons, Sam and Charles, are now 25 and 23 years old, respectively.

In addition to parenting duties and a longtime home in Pound Ridge, N.Y., Caldwell and Whitehead have shared a life in the theater that in some ways echoes Tandy and Cronyn’s famous partnership.

Caldwell won Tonys for Tennessee Williams’ “Slapstick Tragedy” in 1966, “The Prime of Miss Jean Brodie” in 1968 (produced by Whitehead) and “Medea” in 1982 (directed by Whitehead). Whitehead also directed her in the one-woman show called “Lillian,” in which Caldwell portrayed Hellman through a text based on the playwright-author’s writings.

Caldwell, whom Time magazine once called “one of the world’s great actresses,” has also played Cleopatra opposite Christopher Plummer in “Antony and Cleopatra” in Stratford, Ontario, and starred with Jason Robards in “Long Day’s Journey Into Night” at the Kennedy Center and the Brooklyn Academy of Music.

More recently, she appeared in McNally’s “A Perfect Ganesh” at the Manhattan Theatre Club this past season.

Y et she has never been one to travel regularly between screen and stage. “I am a theater actor, not a television or movie actor,” says Caldwell, whose most noted appearances on television have been in filmed versions of her stage performances, such as the 1983 PBS production of “Medea” and the 1985 BBC-TV production of “The Seagull.”

She prefers, instead, to supplement her stage work with teaching, and has for the past several years held the post of Visiting Eminent Scholar at Florida Atlantic University in Boca Raton.

The advice she gives her students is not so different from that which Callas advocates, though Caldwell couches it in different terms. “I teach punctuation, really,” she says.

“As a writer, you know that punctuation is your way of scoring what you’ve written. But so often with actors, they don’t obey the punctuation.

“A playwright has left you [marks] where he wants you to come to a full stop, or [to speak] a whole sentence without a pause. It’s easy if you just relax and let the rhythms take over.”

Callas, no doubt, would have agreed. “That’s really what [McNally’s Callas] teaches when she goes into some sort of paroxysm about the necessity for the students to listen to the music. You don’t have to do anything but listen. That’s exactly what I teach. It’s all in the text.”

Caldwell takes a similar tack when directing, which has included both classic and contemporary works, including “Richard II” at Stratford, Ontario, a Broadway “Othello” with James Earl Jones and Christopher Plummer and “Park Your Car in Harvard Yard” with Jason Robards and Judith Ivey. Most recently, she staged the Off Broadway production of “Vita and Virginia,” with Eileen Atkins and Vanessa Redgrave.

As a director, Caldwell says her technique is both to challenge and to support her cast. “It’s a little like parenting,” she says. “It’s making [the actors] truly believe that they are safe with you and that you will demand things of them, but never things that will hurt them.

“Gradually, they’ll begin to find their own rhythm. Then you’ll ask them to jump higher than they ever imagined, giving them support. And eventually, when they can run and jump and skip and hop better then you can, you’re prepared to release them.”

It’s a method that presumes, though, that actors will bring something of themselves into the rehearsal. And that, says Caldwell, requires a knowledge of tradition.

Yet acquiring that background is increasingly difficult for emerging talents today, she says. “I don’t think that there are enough really marvelous people working consistently enough [in the theater], so that young actors don’t get a chance to see older actors. A lot of young actors today don’t have enough of that shoring up of who they are.”

After all, not many women of the theater of Caldwell’s caliber are setting the example today. And even Caldwell admits that she isn’t as driven as her track record might suggest.

“I’m very happy when I’m directing and I’m very happy when I’m acting, but I know that when I’m out of work I’m also happy,” she says. “I have nothing I desire to do except have a swell time with Robert and go traveling again.”

* “Master Class,” Mark Taper Forum, 135 N. Grand Ave., Tuesdays-Saturdays, 8 p.m.; Sundays, 7:30 p.m.; Saturdays and Sundays, 2:30 p.m. Ends July 1. $28-$35.50. (213) 365-3500, (714) 740-2000.