There is the art of jazz singing before Cassandra Wilson's 1993 album Blue Light 'Til Dawn and the same art afterward. With that album, the Jackson, Miss.-born composer and singer served notice that she'd sing her original material and display exquisite taste in selecting and interpreting the music of others.

She mixed in blues, country, folk, and pop. She created a misty ambience to go with that musical blend, plus a husky low register and adventurous arrangements. Each album that followed captured the Wilson texture, her knack of softly punctuating lyrics, seemingly rendering them still in midair.

All of that - Wilson's smoky tones and vibrant ambience - is back center stage. It's there in her tribute album to Philadelphia-born Billie Holiday, Coming Forth by Day, which appears April 7, on what would have been Holiday's 100th birthday. And it was certainly there Saturday night at World Cafe Live at the Queen in Wilmington, where Wilson did a gala gig in honor of Lady Day's legacy.

This was not hero worship. Wilson let her low voice roam the lonely corridors of Holiday's signature songs - the swinging "What a Little Moonlight Can Do," the broken "Good Morning Heartache" - holding back from the raw emotion that was Holiday's trademark.

That doesn't mean Wilson's reimaginings lacked deep feeling, only that the grace notes were different: a tremulous stretch during a dreamy, Dixieland take on "I'll Be Seeing You"; a quiet crackle in the lullaby C&W of "These Foolish Things," where she emulated violinist Charles Burnham as she sang the phrase "oh how the ghost of you clings."

A swampy version of "Billie's Blues" found Wilson singing low, through gritted teeth and under her breath: "I've been your slave / Ever since I've been your babe / But before I'll be your dog / I'll see you in your grave." And she finished that startling stanza with a gritty "yeaahhhh."

Sonically, a spooky, ever-shifting palate of sound gave Wilson's voice a rhythmic backbone and CinemaScope atmosphere, the latter provided mostly by impressionist guitarist/ambient noodler Kevin Breit. Stripped of its usual peppiness, "All of Me" had the sway of a Michel Legrand film score. The chaotic blues of "Crazy He Calls Me" was an eerily psychedelic epic ideal for Wilson's interpretations.