On the short-list of essential works of the modern American theatre, Ntozake Shange’s 1975 “choreopoem” For Colored Girls Who Have Considered Suicide When the Rainbow is Enuf ranks high indeed. SheCow Productions’ current edition, in conjunction with Burning Coal Theatre Company, at the Murphy School Theatre provides strong evidence for its continued presence in the canon.

A deserved Obie winner during its 1976 run at the Public Theatre — the author was one of the seven women in that original cast, and it’s her face that graced Paul Davis’ iconic poster — Shange’s lyrical ensemble piece is by turns elegiac, celebratory, richly comic, and harrowing. By speaking to women of her age, nationality and race at a specific moment in time, Shange achieved both a stark specificity and a moving universality. Certain phrases lodge in the skull: her evocation of a constricted life in Harlem (“six blocks of cruelty/piled up on itself/a tunnel/closin’”); her description of one pleasure-seeking woman as “a deliberate coquette”; the terrifying last line of “a nite with beau willie brown”; and the exquisite simplicity, at the finale, of “a laying on of hands” as a benediction, a kind of annealing balm — sisterhood at its gentlest and most profound.

Moreover, the playwright has not been content with enshrining her work in a time capsule. Shange has added the quietly devastating “positive” to reflect the dangers to black women of HIV inherent in the shamed self-negation that leads some men to seek sex with other males “on the DL.” She has also updated “beau willie brown,” making her hapless, shell-shocked addict a veteran not of Viet Nam but of the Iraq war and a victim of the crack epidemic. Small measures taken, but they increase the sense of for colored girls… as a living testament.

At Burning Coal, Karen Dacons-Brock has directed, with style and fluidity, a spirited cast of seven that performs Shange’s taut, sinewy yet flowing lyrics with agility and expansive range. With her choreographer Cynthia Penn, Dacons-Brock creates intricate patterns and swirling movement that bind and separate the women onstage with almost unerring sureness. If she falters occasionally (the segue between the end of “beau willie brown” and the beginning of “a laying on of hands” is much too quick to allow the audience to react fully to the shattering horror revealed in the first), in the main she more than succeeds.

Carly P. Jones is earthy and ethereal at once as the Lady in Green; in her embodiment of the sensual Sechita in “one” she becomes something akin to a moving cubist painting. Aurelia Belfield (Lady in Yellow) locates joy and hurt with equal aplomb, while Lakeisha Coffey (Lady in Orange) has a special gift for expressing tremulous pain. Kyma Lassiter and Tara Whitney Rison (Lady in Brown and Lady in Purple, respectively) are slightly less effective — I think it’s a mistake to perform “Toussaint” in a high, childish voice — but all of the women are forceful and committed, and each has her moment, or moments, in which to shine.

Best of all, however, are Emelia “Me-Me” Cowans (Lady in Red) and — especially — the splendid Sherida McMullan as the Lady in Blue. Cowans lends a rhythmic precision to her performance, as well as a trembling vulnerability all the more moving for its restraint.

McMullan is, simply, astonishing. Every movement, every line, shines with assurance and an absolute ability to locate the perfect gesture, expression and inflection for each occasion. Her vocal rhythms — now rapid, now slower, stark and complex as needed — are just about perfect. There must be very little beyond her range, and it will be an exhilarating pleasure to chart her progress.

The show continues through May 20. For details, see the sidebar.

Note: For SheCow’s promo, click here: http://www.youtube.com/watch?v=D7cw0Gi4ECw. (You may skip the opening ad.)