Rita Moreno is giving a master class in the finer points of holding and sharing a stage at the Berkeley Repertory Theatre. Moisés Kaufman applies the inventive creativity with which he devised "Gross Indecency" and "The Laramie Project" to open up and theatricalize the script. Between them, the "Master Class" that opened Wednesday at the Rep's Roda Theatre often lives up to its name to a degree I've never seen before.

A tabloid-light portrait of Maria Callas framed within the master classes the great soprano taught at Juilliard in 1971 and '72, Terrence McNally's '96 Tony award winner is essentially a diva vehicle with some lovely operatic trimmings. Originally written for Zoe Caldwell, who played Callas on Broadway, it came off as something of a "Diva Dearest" in the touring production headed by Faye Dunaway that came to the Golden Gate Theatre in '97.

Moreno, however, is a diva of a different sort. She's earned the title, as one of the select few women to have won the top four performing arts awards -- Oscar, Tony (for McNally's "The Ritz"), Grammy and Emmy (along with Helen Hayes and Audrey Hepburn, with Barbra Streisand and Liza Minnelli squeaking onto the list with special honorary awards). In June, she'll have to interrupt her performance schedule to fly east to accept the Presidential Medal of Freedom. And she's an artist of exceptional sensitivity who can find the quietly dramatic pulse of an overwritten passage and wring the heart with a suppressed sob.

She's more than capably supported at the Rep by three strong singers as her master class students and a wonderfully smitten, nervous Michael Wiles as the proficient piano accompanist. But what makes this "Class" work as well as it does is the way Kaufman has eschewed the realistic settings of Leonard Foglia's original production in favor of a more theatrically metaphorical approach…

…Donna Lynne Champlin is comically overwhelmed and klutzy as the first student, warbling her Bellini aria in brightly phrased illustrations of the problems Callas will point out (deft musical direction by Gary Sheldon) -- once she lets her get past the first note. Scott Scully is a beguilingly clueless and dedicated tenor, delivering a captivating "Recondita armonia" from "Tosca." A fiercely focused and vital Sherry Boone rises to compelling heights of murderous resolution in a resonant, full-bodied soprano as Verdi's Lady Macbeth...