Two icons of musical genius: Mary Lou Williams sought the sacred; Marvin Gaye probed the world, the flesh and the Devil.

Soul on Soul: The Life and Music of Mary Lou Williams by Tammy L. Kernodle Northeastern University Press, April 2004, $30 ISBN 1-555-53606-9

Like many geniuses, pianist Mary Lou Williams was ahead of her time. Born Mary Elfrieda Scruggs in 1910, she demonstrated her musical gift as a child by mimicking tunes her mother played on the organ--note for note. By the time she was 12, Mary was playing one nighters throughout the Midwest. In the 1920s, while many black women were earning $8 or $9 a week for their domestic or field work, Mary sometimes pulled in as much as $30 a week for her piano performances. At 14, she earned a place on the black vaudeville TOBA circuit, a.k.a. the "Tough on Black Actors of Asses" circuit; at 17, she married saxophonist John Williams. Although the marriage ended after 14 years, the support and protection Mary received by having her husband with her on the road in those early years proved invaluable.

For the most part, however, Williams was always her own woman. She boldly spoke up when she thought she and her bandmates were being underpaid, and she wouldn't play the sex-appeal card in the media--a la Hazel Scott--in order to attract a wider audience. When bebop came along, Williams was one of the few older jazz musicians to embrace that art form, and she befriended Miles Davis, Dizzy Gillespie, Charlie Parker and Thelonious Monk among others. Her legacy is unassailable: Williams is the only performer to have played in every stylistic period of jazz from the 1920s through the 1970s. By the time Williams died of cancer in 1981, she'd recorded more than 100 records.

Yet there were also periods when she dropped out of music. In 1955, after Parker died flora a heroin overdose, Williams, in an effort to find God, started fasting, eliminated all vices and committed herself to helping others. Previously known for her stylish clothing, Williams pared down to one pair of shoes and a single dress, which she hand-washed daily. Her niece said: "She was like a bag lady--not crazy, but odd, running here and there with bags of groceries, trying to help these strung-out musicians. People laughed al her." The author also notes: "Not willing to see another talented musician die of an overdose of complications brought on by consistent drug use, Mary operated a one-woman rehabilitation center in her Hamilton Terrace apartment."

Passages like these are what make this book exceptional. The author illustrates the inner struggles of this complicated woman. Kernodle reveals Mary Lou Williams as a person--warts and all. That is, in the end, what really makes the book reverberate with the reader, soul to soul.

--Reviewed by Joy Duckett Cain. She is a freelance writer and a frustrated composer in Westchester, New York.

Mercy, Mercy Me: The Art, Loves & Demons of Marvin Gaye by Michael Eric Dyson Basic Books, April 2004, $23.95 ISBN 0-465-01769-X

One of Motown's best selling artists of time was profound, prophetic and driven by ferocious demons. The cover of his 1981 album In Our Lifetime, illustrated by Neil Breeden, as well as songs like "Mercy, Mercy Me" and "Let's Get it On" reflect Gaye's compelling vision: The peace-loving, spiritually possessed Gaye seemingly faces his driven self. Below these diametrically opposed images are nuclear plants afire, people protesting and towering buildings and the Statue of Liberty being blown up, as an aircraft approaches.

Although a much troubled man, indeed, this soulful bard, who once built his raison d'etre around equally gifted singer Tammi Terrell--left a complicated legacy that makes you wonder had he lived would his music become a sanctified source of his own healing and that of millions of others. If you're going to write a book about Marvin Gaye, you have to explore, not exploit, his life in a social context that provides the same kind of incisive passion and vision as Marvin's music.

Michael Eric Dyson provides some interesting details and an assessment of the impact of Gaye's music on popular culture, the war in Vietnam, Black Power and the "Inner City Blues." But Dyson's words often get in the way of a riveting story about this erotically complex, passionately romantic and musically sensuous man.

Although Gaye's life was tragically cut short by his father, who physically and psychologically abused him, the music and emotion that was Marvin Gaye will always be with us.

--Reviewed by Daphne Muse Daphne Muse is a writer, social commentator and poet. Her commentaries can be heard on NPR's The Tavis Smiley Show.