"I bet you could ask 20 blacks today, 'Who is Jimmy Witherspoon?' and they can't tell you," laments Witherspoon, the Arkansas-born blues singer. "I was being interviewed on a black radio station in Boston and I asked, right on the air, 'Why don't you play blues -- you ashamed of it?' Young blacks today are not aware of the blues. They only hear rock 'n' roll and Top 40 and they don't go to the library and read on the black culture like they should.

"The blues started with blacks and there are so many black blues singers, and young blacks wouldn't know their names. I've seen this happen -- young whites in college have turned young blacks on to the blues. And that's beautiful."

Witherspoon, who opens at Charlie's tomorrow and stays through New Year's Eve, should be a household name.

Consider the awards and accomplishments of his 40-year career: Melody Maker, down beat and other magazines have had him at the head of their polls, he won the NAACP Image Award in 1975, and he was elected to the Ebony Hall of Fame in 1977. In 1961 Witherspoon was among the first blues singers to be featured at Carnegie Hall, and his concert tours since then have taken him around the world. A prolific composer, he has more than 500 singles and nearly 40 albums, including such top-of-the-chart hits as " 'Tain't Nobody's Business" (1952) and "Love Is a Five Letter Word" (1975). His most recent album (with Panama Francis' Savoy Sultans) was a Grammy nominee this year.

"I don't know why I started singing the blues," Witherspoon says. "Blues wasn't hardly allowed in my home. My mother was a very religious lady, so was my father. I started in the church at the age of 5 singing spirituals."

He was soon winning local singing contests and ran away from home at age 12, finishing high school in California. "Then came World War II and I was in Calcutta, India, in the Merchant Marine, feeling kind of lonesome and I heard pianist Teddy Weatherford, who had been in the East for years, playing Benny Goodman's arrangement of 'Why Don't You Do Right?' " Witherspoon sat in with the West Virginia-born Weatherford's band, singing "Around the Clock," a Wynonie Harris number that Witherspoon describes as a "very risque', suggestive blues."

"Before that I was trying to do ballads," recalls Witherspoon, "which I think most black people were at that time, trying to lose their identity and I was no exception."

Blues critics and historians have, in Witherspoon's opinion, "written ridiculous stories. You have to be poor, you have to be black and you have to be from Arkansas or Tennessee or Mississippi to be able to sing the blues. It doesn't mean that several blues singers -- I won't call names -- who can't read or write are greater blues singers than I am.

"People say to me, 'You always sing sad blues.' That's ridiculous. I have the same type limousine the president has -- with a chauffeur! But it has nothing to do with singing the blues."

Perhaps what most distinguishes Witherspoon from so many of his fellow blues singers is his familiarity with the jazz idiom. Early in his professional life he spent four years with the Jay McShann Band and later he worked for three years with saxophone giant Ben Webster. And that's only the beginning of a long list of Witherspoon's jazz associations.

"The average blues singer can't work with these men," Witherspoon argues. "They don't understand the notes." On the other hand, he points out, the jazz musician must be equally comfortable with the blues. "I'll tell you something, you show me a jazz musician who can't play slow; he's not a jazz player."