In a sense, Singer Sheila Jordan has a bit of blackness in her heart and lungs. Literally she has American Indian redness in her blood, and she swam in a sulfur creek as a child.

That's the peculiarly colorful heritage of a coal miner's granddaughter whose originality has taken decades to emerge into the full light of mainstream jazz acceptance. Little as its known, her influence runs like a charry vein running through much of Blue Note Records' current stable of top jazz singers.

Jordan, who will perform at 6:30 p.m. Wednesday at Jazz at Five on State Street, was born and raised in harsh mining country. Tiny Summerhill, Pa., was a mile away from South Fork, the coal mining town where her grandfather labored in the depths while raising Jordan with her grandmother.

These are improbable but utterly American roots for an artist. Flinty film actor Charles Bronson is from South Fork, and his sister was Jordan's best childhood friend.

Those tough years weigh heavy on her sensibility.

"I grew up in a family that did their best, but they were very poverty stricken and alcoholic," she says in a phone interview. "I was really unhappy as a child. My father was very alcoholic. The music is hereditary I'm sure, like alcoholism is hereditary. I've had my own demons. The music saved me."

She sang at PTA meetings, and her idiosyncratic way with tonality arose early, and she was heckled by her classmates. Churches of her region didn't permit female choirs. So she sang in her own private world embraced by the echoes of the Allegheny Mountains, which helped nurture the unfettered intimacy she would make her own.

Bass players especially would become a sonic shadow for her lonely musical wandering. She moved to Detroit to live with her mother and discovered jazz, which set her on her course.

She was lucky enough to cross paths with Charlie Parker, who heard her gift, which he dubbed "million dollar ears."

Bird became her "musical guru," and she married Parker's pianist Duke Jordan. That union lasted briefly but produced a daughter, Tracey, the most important person in her life. Jordan immersed herself in bop's intricacies and formed a vocal trio with Skeeter Spight and Leroy Mitchell, which set bop solos to lyrics -- before Lambert, Hendricks and Ross.

"I always knew the plight of black people through being poor myself," she told Sally Placksin in "American Women in Jazz." "I wanted to be black."

The trailblazing composer-arranger George Russell gave her the direction she still follows.

Her haunting rendition of "You Are My Sunshine" from Russell's 1962 album "The Outer View" reflected her light-and-shadow life and validated her way of delving into the cracks between notes and conventional emotions. Jordan often sings quartertones, which draw from the sepia tonalities of American Indian singing and chanting. But Jordan's arrow-sharp pitch keeps her vocal aim true in even the most far-flung musical flights.

Russell stripped down pointless ornamentation and laced the music with spare bitonal strains of what was becoming modal jazz.

Jordan's austere yet tender expressivity fit the mode of ECM Records, which produced "Home," setting the poetry of Robert Creeley with bassist Steve Swallow, and "Playground" with pianist Steve Kuhn.

Jordan reached full artistic maturity in a series of often breathtaking albums with bassist Harvie Swartz in the 1980s.

In Madison, Jordan will play with some of the city's finest vocal accompanists: pianist Paul Hastil, bassist John Mesoloras and drummer John Becker. The Matt Pinizzotto Organ Trio will open at 5 p.m.

What's rarely acknowledged is her place in jazz. Hear Jordan's work, then consider the stylized shape-shifting tonal intimacies of Blue Note's current stars: Cassandra Wilson, Patricia Barber and Jackie Allen. Jordan's deep-woods daring foreshadows them like a twilight you feel more than see or hear. She says Barber is the only one among those who has openly acknowledged her elder's influence, but she laughs off her comparative obscurity.

"I'm not a star or a diva," she says. "I feel I'm a messenger of the music. That's all I want to be called."

This messenger from the mines has always worked a 9-to-5 job so that she "could support the music till it could support me." That helped her retain artistic integrity. Now she's retired and blessed with more work than she can handle -- though most of it is in Europe.

Meanwhile, Jordan's personal life with her daughter still grounds her, a relationship recently fraught with Tracey's breast cancer. Both women faced life passage recently with the death of Duke Jordan last week. Tracey was just healthy enough to attend her father's funeral in Denmark, which took place on the day of the phone conversation. Jordan never seriously considered attending.

"He never did anything for us," she says bluntly.

Jordan was always her own woman, which made all the difference. As she memorably told Placksin: "Two things I'm eternally grateful for: that I was given this wonderful gift of expression and that I was given it through a woman's body and mind."