Ever since Cassandra Wilson, Holly Cole and Diana Krall started topping the jazz charts, record companies have been signing almost any woman with a strong, silky voice and a repertoire of a dozen Cole Porter songs. LaVerne Butler stands out in this suddenly crowded field because she is no warmed-over pop singer; the Louisiana veteran has a sure grasp of jazz's two essential elements-blues and swing. The 6-foot-tall vocalist knows how to drag the crucial notes in a melody downward into the blue zone between desire and satisfaction. And no matter how she twists and turns the tune, she never loses that syncopated rhythm.

Butler's telltale choice for the first song on her third album, "Blues in the City," is Clyde Otis's "This Bitter Earth," a song recorded by both of her two clearest models, Dinah Washington and Aretha Franklin. Butler doesn't overwhelm the song the way Franklin did, but instead uses a conversational tone and subtle emphases to make us pay closer attention to the lyrics about hard luck and resilient optimism.

If Butler doesn't raise the roof, her impeccable timing and inventive phrasing allow her to fill all the songs with tremendous feeling. Backed by Bruce Barth's tasteful, sympathetic piano trio, she successfully tackles such jazz standards as Harold Arlen's "One for My Baby" and Ann Ronell's "Willow Weep for Me." But Butler's at her best on blues numbers such as Percy Mayfield's "Hit the Road Jack" and Bessie Smith's "Backwater Blues," where her marriage of urbane style and earthy grit is near perfect.

Appearing Monday at Blues Alley. To hear a free Sound Bite from LaVerne Butler, call Post-Haste at 202/334-9000 and press 8121. (Prince William residents, call 690-4110.)

CAPTION: LaVerne Butler, a woman who knows the essence of jazz.