It's notable that Quantum is staging Yerma: It's a rarely produced work by a famed playwright who is seldom performed in these parts, Federico Garcia Lorca. But the most striking thing about it is likely the presence of Ethan Margolis and Cihthli Ocampo -- and how this singer/guitarist and dancer are used in the show.

The two, husband and wife, are acclaimed flamenco artists, based in Spain, specializing in this art form closely associated with Gypsy culture. (Both Margolis and Campo, somewhat unusually given their prominence in their field, are U.S.-born; Margolis grew up partly in Ohio.) Director Melanie Dreyer deploys them expressionistically, in "roles" particular to their talents and found nowhere in Lorca's script about a rural woman's obsession with bearing a child.

Margolis is actually the first performer we see, entering the stage-in-the-round only to mount a sort of pedestal in the risers where'll he spend most of the intermissionless show, alone with his acoustic guitar. All the music was composed for Yerma. Margolis' dramatic strums and burbling runs of single notes comment on the action. He even (as he told me when I visited the East Liberty space during rehearsals) provide musical motifs for each of the characters: desperate Yerma; her workaholic farmer husband; a strapping young shepherd; and so on.

Yet it's Ocampo you won't be able to take your eyes from. In one of the show's better visual gambits, the dancer (first name pronounced "Seely") is introduced in silhouette, backlit behind the translucent white drops that enclose the seating and stage like a tent. The entrance showcases the serpentine hip movements, liquid arms and butterfly hands that characterize her performance -- accentuated by her fluttery-sleeved blouse and a skirt that's floor-length but skin-tight from waist to mid-thigh.

The show's centerpiece is a long solo in which Ocampo adds to her repertoire footwork that thunders on the wooden stage -- it sounds like artillery tapdancing -- plus peremptory fingersnaps and percussive tongue clicks. All the while the look on her face remains fierce, defiant, sensual -- all the things Yerma herself would like to be, or express, but can't. 

Yerma has its problems. Dramatically, the biggest might be that, as the action opens, Yerma (played by Melinda Helfrich) has already crossed the line into obsession. Her desire to have a child -- the only sort of fulfillment open to a woman in her time and place -- and her husband's refusal (and apparent inability) to fulfill this wish has pushed her over the edge. The character's got nowhere to go but into higher keys of desperation, and if the sentiment is naked the drama can get repetitive and even grating.

Still, one's glad Dreyer reworked the show as she did, if only to incorporate Margolis and Ocampo. A theater person in the audience told me afterward that Quantum's version of Yerma (which runs through April 26) is much abridged from the original. Yet its 85 intermissionless minutes made considerable time for the dancing and music. I was especially glad of this during Ocampo's big solo, during which Margolis leaves his perch for the lone time, descending to stage level to accompany her dancing with handclaps. And time stops beautifully.