The late stride pianist James P. Johnson described the style to an interviewer shortly before his death in 1955:

"We'd wear a light pearl gray homburg hat set at a rakish angle and some carried a gold-headed cane. Players would start off by sitting down, wait for the audience to quiet down and then strike their chord, holding it with the pedal to make it ring.

"Then they'd do a run up and down the piano -- a scale or arpeggios -- or if they were real good they might play a set of modulations, very offhand, as if there was nothing to it. Some ticklers would sit sideways to the piano, cross their legs and go on chatting with friends nearby. It took a lot of practice to play this way -- while talking and with your head and body turned. Then, without stopping the smart talk or turning back to the piano, he'd attack without any warning, smashing right into the regular beat of the piece. That would knock them dead."

Implicit in that description is the essence of stride, an Afro-American musical form that came into being early this century as the entertainment staple of Harlem rent parties and saloons, and that, handed down over the decades, remains an element in the playing of all jazz keyboardists. First, there is the showmanship, then the virtuosity, and finally the irresistible momentum of the piano's seesawing chord and single-note rhythms of the left hand and the against-the-beat melodic figures of the right.

Johnson, considered the dean of stride pianists, as well as Luckeyeth (Luckey) Roberts, Willie (The Lion) Smith and Fats Waller, will be paid tribute in Baird Auditorium at 7:30 p.m. Sunday. The second in the Smithsonian Resident Associates Great Jazz Composers series, the concert will feature pianist John Eaton, clarinetist Wally Gardner and string bassist Tommy Cecil. Call 357-3030 for ticket information.

"I don't have any idea what John is going to do," says the Smithsonian's resident jazz authority Martin Williams, who conceived the series and will introduce the evening, "but I'm in favor of it. John has such a local audience, what you do is open the door and stand back."

Eaton himself has revealed that though his emphasis will be on Waller, representative compositions of the others will be included in the program. He will "give a short demonstration of what stride piano is," along with some reflections on what it is not, citing the currently popular piano style of George Winston as a glaring example of the latter.

Another thing that stride is not, Williams says, is the one-dimensional picture many people have of Waller from the Broadway musical "Ain't Misbehavin'," which largely depicted the great pianist and composer in only one of his three musical personalities, that of entertainer.

"That show was theatrically effective, but to me it wasn't Waller because Waller's like a guy who picks a piece of lint off his jacket and flicks it away and that's it," says Williams of Waller's clowning. "It's spontaneous, off the top of the head and it usually is very funny, but you have to understand that it's quick and it's gone."

Williams doesn't deny that Waller was a preeminent showman, but he considers Waller's more lasting significance to be in his compositional achievements and in his interpretive role. Williams calls attention to such popular songs as Waller's "Black and Blue," "Keepin' Out of Mischief Now" and the title tune of the musical mentioned above.

"One of the greatest Wallers to me is the guy who recorded piano solo versions of other people's pieces," says Williams, citing "a marvelous recording of 'I Ain't Got Nobody' and a beautiful 'Basin Street Blues.' The really durable Waller is the guy who wrote those little postragtime piano pieces, 'Handful of Keys' and 'Viper's Drag' being a couple of the best known." Williams also enthuses upon Waller's genius for structure and his "really dazzling kind of intricate, showmanly virtuosity . . . in taking a simpler idea and making it more complex and taking the more complex idea and distilling it down to simplicity."

"They were careful composers," explains Eaton of the stride pianists, "and they were performers who realized that the music, to be worth anything, has got to be communicated to the audience, and they were marvelous pianists. James P. Johnson was more ragtime oriented, the eastern version of ragtime, and Fats' style is rooted in James P. and is more harmonically sophisticated. And that's also true of the Lion, who was a major influence on Duke Ellington and on Thelonious Monk. And, of course, the Lion was also a marvelous entertainer and personality, although he did not have the comic genius of Fats.

"Stride is a style, but it's not a style," Eaton says. "With Luckey Roberts, James P., Fats and Willie the Lion you have four stride pianists, but they're utterly different. Put them back-to-back and you can hear the difference."