Introducing the Jazz Arts Society piano concert Saturday night at the Washington Ethical Society, jazz deejay Rusty Hassan pointed out that there would be "some overlap as one style evolves into the other." The statement was prescient: dovetailing, foreshadowing and recapitulation characterized the program.

John Eaton began with Joplin's "Maple Leaf Rag," his left hand marching, his right producing the "ragged" rhythms. James P. Johnson's "Carolina Shout," a "stride piano" piece, was rhythmically looser, while Fats Waller's "Honeysuckle Rose" cast off the straightjacket of ragtime and swung musically in Eaton's hands. His concluding number, "I'm Late at the Embassy Row Blues," shifted tempo from back-room slow drag to walking bass romp.

South African expatriate Ndikao Xaba, protege of Dollar Brand and associate of Myriam Makeba, went directly to West African sources for a set that combined theater, song, dance, declamation and a variety of instruments, including bells and bullhorn. His approach to the piano, he conceded, was percussive. On one number he flailed the keyboard with his forearm. On other pieces he achieved a hauntingly repetitious tremelo, full of blue dissonance. Bursts of breath, hisses, tongue-pops and keening simulated horn passages and a cannonading hand drum solo rocked the rafters.

A former accompanist for Billie Holiday and Sarah Vaughn, Howard University professor Kirk Stuart capped the evening with his own extended work, "Theme and Fugue to a Broadway Basement," neatly framed by introductory selections illustrating styles of the '40s and '50s and his encoure offering, a mean and jumping "St. Louis Blues."

The concert was the first in a series devoted to the instruments of jazz. Next up will be the strings of the idiom.