Give an actress who has good pipes a strong script and a hot character, give her great blues songs, a cool on-stage jazz ensemble and clever staging, and you've got a knock-out hit. Penumbra Theatre's production of Oliver Goldstick's musical drama Dinah Was has it all. Regina Marie Williams burns hot and heartrending as Dinah Washington, sexy queen of the blues.

At base, Goldstick's play is a sit-in. Dinah refuses to budge from the front lobby of the Lake Sahara hotel in Las Vegas in 1960. She's the hotel's sellout nightclub draw, and the first black woman to sing on the Las Vegas strip. But she has broken a rule, entering the hotel via the whites-only front entrance and, to add insult to injury, the hotel refuses to give a black woman a room. Dressed in only a white mink coat and black slip, she perches on her suitcases in the lobby, tippling from a hip flask, as she recalls, in flashback scene and song, her ambitious but difficult life. She is also stuck in the front lobby of her career; her great struggle is to reclaim her art from the control and limitations imposed upon it her by a white recording industry and to move beyond the pigeonhole of blues to jazz and pop.

On opening night, Williams grew stronger and stronger in voice as she took on the role of feisty Dinah until, by evening's end, the audience spontaneously snapped its fingers and hollered its pleasure in response to her singing.

She's a ringer for the part, and Lou Bellamy directs with a sure hand. A former member of Sounds of Blackness and a 12-year veteran at Penumbra, Williams also brings to her role bags of snap, sex and dazzle. She pitches her performance to dish out Dinah's sass and arrogance and to reveal her painful vulnerability.

Those vulnerabilities include her rigidly Christian mother, played by wonderful Greta Oglesby. Her mother's hypercritical voice re-plays like a stuck 78 rpm record in Dinah's head. Mrs. Jones cannot forgive her daughter for changing her name from Ruth Jones to the snazzier Dinah Washington, and for not living a Christian life. Then there are her sons, who she leaves with her mother in Chicago, and a slew of failed marriages. Dinah longs for unconditional love and the broad audience and financial reward that she knows her talent merits.

As Dinah's sits in the lobby, she gets drunk, but in flashback you see her in compelling performance, in tense confrontations with her mother, in a deliciously hot flirtation with a tenor sax playing lover, and popping pills Marilyn Monroe-style to deaden the ache in her soul. Dinah was a quick-tongued, generous, spontaneous and flawed woman, and Williams gives her full range.

Williams revels in a wickedly funny number in which Dinah visits a dentist to "get her cavity filled," and she pulls at the heart in songs like, "I Won't Cry Anymore." The most beguiling and dramatic among many strong scenes has Dinah revealing, mid-act, the racism she is subjected to at the hands of the Sahara Hotel, and she brings on stage Violet, an admiring black kitchen worker, to sing "A Rockin' Good Way." Austene Van Williams Clarke plays the green Violet convincingly with appeal and angular awkwardness.

It's William's night, and she works with a strong cast. There's not enough of T. Mychael Rambo's velvet voice, but he's grand as Dinah's ex-husband and as her lover. Phil Kilbourne and Gus Lynch play two roles apiece as white status quo figures, and Sanford Moore leads a cool, bluesy jazz ensemble that highlights Andrew Schwandt's liquid tenor sax.

The musicians play in a loft above Ken Evans' versatile period set and, in concert with Mark Dougherty's lighting design, the set rotates and folds-out to accommodate multiple scene switches. The musician's loft doubles as the red-necked hotel manager's office, and curtaining drops from above to create the glitz of the Sahara's nightclub.

Sharon Selberg provides period props, from microphones to a circular hotel seat, and costume designer Michael Alan Stein has had a field day, kitting out clothes-mad Dinah in elegant '60s dresses, jewelry and plush furs. The final gown is a svelte show-stopper.

With its fierce dramatic arc, defined characters, wit and superb song, Dinah Was is an irresistible night out and, oh, the pleasure of an un-miked musical in an intimate theater.

Dinah Was October 23 - November 23. Thursdays - Sundays. Thursdays, and Sundays. 7:30 p.m. Fridays and Saturdays 8:00 p.m. Sundays. 8:00p.m. Saturdays and Sundays, 2:00 p.m.. $30 - 35. Penumbra Theatre, 270, North Kent Street, St. Paul. Call 651-290-8686 x 228, or at www.penumbratheatre.org.

- Elizabeth Weir