The hoary (and well-justified) complaint about the dearth of strong women’s roles is about to lose some of its punch. Unfortunately, the new bonanza comes all in one place and for just four actresses. In Michele Lowe’s satisfying new play “String of Pearls,” a quartet of women play more than two dozen characters, each of them coming into contact with the same titular necklace.

We see how it changes them even as it remains unchanging – though for a dumb object, it seems to demand an awful lot. It’s an odd thing that none of the ladies waltzing across the stage can quite explain the beads’ appeal. They describe them as “white” and “perfectly round.” But their best quality is their imperviousness. In the end, the play makes a gentle point about interconnectedness and fate. Most striking are the ways Ms. Lowe finds to call bravery out of her characters with a simple strand of pearls.

An uptight Yankee wife (Ellen McLaughlin) can wear them as a symbol of two different sexual awakenings; an overtaxed burial parlor attendant (Sharon Washington) can hawk them for a week of rest; yet they can still seem pristine enough for a young bride (Antoinette LaVecchia, channeling Kristin Davis). As they pass from hand to hand (to greedy fish), each woman has to re-assign their value, and also her own. Luckily, all this female bonding goes on with a maximum of humor.

Though Ms. Lowe delves into several danger zones (mothers dying of cancer, daughters of Holocaust survivors), she keeps her sentiment on a tight rein. Each vignette features some little highlight of laughter to keep the play taut.

It helps that Primary Stages has assembled the National Trust of actresses. Ms. LaVecchia swings from chain-smoking auntie to highly-wound soccer mom with nervy skill, while Mary Testa is actually unrecognizable as she shifts between characters. Ms. Testa’s comedy can be Bronx-broad or Uptown-narrow: One minute she’s a ballet matron, working in rigid little grace-notes of behavior; the next, she’s intoning entirely out of her nose.

Even in company this splendid, Ms. McLaughlin emerges as queen bee. The changes that she makes to differentiate her characters are actually quite small – just a touch of accent, or a slight hunch in posture. But her specificity leaves no doubt of their delineation, and each of them retains something of her rangy strength and peculiarly American beauty.

Loy Arcenas’s set has several unfortunate elements – some gliding panels painted in splodgy gray and an unprepossessing pool sunk into the stage floor. But behind it all he paints a rectangle of abstract blue streaks, partially obscured by a scrim. As D.M. Wood’s lights shift on the gauzy surface, he shows overlaying brushstrokes of rose and gold. It is a terrifically subtle and ever-changing effect, glowing, itself Pearle scent and lovely. For a piece about effervescence, it’s a gem of a visual cue.

Costumer David Zinn gets to work in a sillier vein, massively aided by the many possibilities of Ms. Testa’s hair. And like her occasionally spherical coiffure, the direction and design of the show only hit their groove a little way into the evening. But by the 11th hour piece, in which a desperately lonely Ms. McLaughlin dives again and again into an imaginary swimming pool, the team is working in astonishing, effective concert. Out of seemingly unremarkable building blocks, they make something beautiful.