Guitarist Bill Harris knows a thing or two about the summertime blues.

Six years ago, he was fighting off the IRS in what proved to be a futile effort to keep open his Northeast jazz nightclub, Pigfoot. Now the stakes are even higher. Due to ongoing financial problems caused in part, he says, by his failure to incorporate the nightclub, Harris and his wife Fannie soon may be forced to give up their house. But not without first saying farewell.

Tomorrow afternoon, the Harrises and many of their friends, including a number of musicians, will gather in the couple's back yard to stage a benefit picnic and concert. The proceeds will go to what Harris is calling his "location/relocation fund ... The money will help us with moving expenses," he says, "and if we raise enough maybe we can recoup the property."

Although its aim is different this year, a Labor Day picnic hosted by the Harrises is nothing new. In fact, for most of the '70s it was an annual tradition in Northeast. Sitting in his kitchen on a recent afternoon, the 62-year-old guitarist thumbed through a folder thick with photos from picnics past, pointing out the celebrities who showed up. Guitarists B.B. King and Kenny Burrell, former D.C. mayor Walter Washington -- there was never a shortage of familiar faces, and yet for every well-known musician or politician there were always a couple of youngsters milling about. Kids like drummer Keith Kilgo, who aspired to be a professional musician and ultimately became one.

"The picnics were great," recalls Burrell, who first met Harris in Detroit in 1950. "To sit in and jam -- that's something Bill has always encouraged at the picnics and at Pigfoot. He's always wanted young people to play, and they'd enjoy themselves up there as much as we'd enjoy watching them ... You know, besides what he's done for the jazz guitar, fusing jazz and classical styles, he's made a great contribution to the music as a teacher, especially around the Washington area."

"Man, it was hot that night," Harris says, leaning back in his chair, recalling Pigfoot's glory days. "Sterling Brown reading his poetry while Sunnyland Slim played the piano. So much happened in that place ... Another night Sarah Vaughan and Oscar Peterson came by because they knew {pianist} John Malachi was there ... "

The decorations that once adorned Pigfoot now clutter the Harrises' basement. Paintings of Sonny Rollins, Dizzy Gillespie and Lester Young hang on the walls, the club's six-foot-high logo is propped up nearby. Rather than move all of it, Harris intends to auction off some of the Pigfoot memorabilia at the picnic. "It was a soulful, relaxed place," says Burrell, who performed there frequently. "I just hated to see it close."

If Harris takes pride in one achievement, it may be that he considers himself "the only guitarist who ever had the guts to play jazz for Andres Segovia." It happened in Washington, in the late '50s, at one of the annual parties that noted guitar teacher Sophocles Papas threw in Segovia's honor. It was customary for Papas' students to gather in a circle around the master and for each to play a classical piece, usually with an embarrassing lack of finesse.

That night, rather than further test Segovia's graciousness, Harris kept passing the guitar along. Finally, when it came around for the fourth or fifth time, he relented. He told Segovia he would play a jazz piece that he was inspired to write after hearing Segovia in concert for the first time. Papas wasn't pleased -- jazz would never do. But Harris persisted. "I just wish someone had taken a picture of Segovia congratulating me when I finished," he says now, savoring the last laugh.

One morning last spring, Harris awoke and played one of Segovia's Bach transcriptions. While practicing he had a premonition of Segovia's death. Shortly afterward, he heard the news on television. He shakes his head. "I was very fond of the old man, shall we say."

Like a lot of religious folks growing up in the South 50 years ago, Harris wasn't allowed to listen to blues and jazz, so he did it on the sly. Raised in Nashville, N.C., the son of a sanctified preacher, he played some Bessie Smith records his parents had purchased before they were saved. When he was sent into town on errands, he could never get enough of the street musicians.

"I was just fascinated by that stuff," he says. "All these people getting music out of their instruments. There'd always be someone on the corner playing the blues and everybody would be singing it. I didn't realize until much later that I was absorbing all of this, hearing guys with names like Billeye and Laughin' Lanky."

Harris played his first guitar bottleneck style, using a knife handle on the strings, which were positioned too high to fret. If he couldn't coax a melody out of an instrument, he discovered early on that he could always beat a tune out of it. He sang and played organ and drums as a teen-ager and later became a bugler in the Army. Moving to Washington following his discharge in 1945, he had every intention of becoming a pharmacist. But he soon turned to music instead, enrolling in the now defunct Washington Junior College of Music, where he studied classical music -- voice and piano -- on the GI Bill. Shortly afterward, he began studying classical guitar with Papas.

In the '50s, those heady days of rhythm and blues, Harris was in the thick of things, working as an arranger and accompanist with the Clovers. As a composer, he gave the vocal group a string of hits, including "Don't You Know I Love You." He was in the limelight, traveled incessantly, but never saw much money. (Ironically, Harris may yet see some income. The Clovers and several other seminal R&B artists are currently negotiating with Atlantic Records for payment of royalties from that period.) Harris toured with the Clovers for seven years, all the while exploring the solo guitar in his spare time. Then, in 1956, Mercury released his first album.

"It was the first solo jazz guitar album, though I didn't know it at the time," Harris says. "I thought it was pop music, but they released it as jazz." The record, one of four albums he cut for Mercury, won instant acclaim. Yet Harris chose to remain with the Clovers for another year. "I guess that's where I made my mistake," he says, without much sign of regret. "I guess I should have left the group to work on the jazz side, but even when I did leave I didn't follow up on it. I came home to be with my family." Bill and Fannie have three children, grown now.

While Harris was on tour in France in 1973, the story goes, someone asked him to sing a blues tune. He complied, but the results were embarrassing. "I could play the blues, but I didn't give much thought to singing until then," he says. "I mean, these people wanted to hear the real thing -- the natural-born blues -- and I wasn't prepared. So I promised myself that when I got home I'd really get into it."

He began by researching the music and by digging into his own past. "When I was a kid," he recalls, "we had this big front yard, this pasture, and when the weeds would grow high, we'd all play jungle. Well, I had this holler that anyone in town could hear ... I can't do it now -- my voice isn't that shrill. But part of the yodel I do now comes from those days, when I was young and uninhibited."

For years, when Harris was touring with the Clovers, he would hang out with blues musicians like B.B. King or Lowell Fulsom and Ray Charles. There was just something about the music, something that spoke to him. He never knew what the attraction was until later, he says. In fact, it wasn't until he opened Pigfoot and began singing blues songs that he realized the strong hold the music had on him. "That's when I understood that the blues was a part of me all along," he says. "That's when it all began to make sense."

The picnic will begin tomorrow afternoon at 3 and continue until dusk. (In case of rain, it will be held indoors.) Among those scheduled to perform, in besides Harris, are Charlie Byrd, Shirley Horn, Nap Turner, Milton Smith, Archie Edwards, Harmonica Phil Wiggins, Charlie Sayles, Bo Diddley Jr. and former Ellingtonian Jimmy McPhail. Admission is a $10 donation, with discounts for senior citizens and children. For more information call 529-4830 or 529-4713.