Cedar Walton, who leads his quartet from the piano, is a "musician's musician." He still doesn't figure high in the popularity polls, but hundreds of jazzmen have tapped his talents for their record dates, more than validating his feathery touch, soulful pulse, and inexhaustible knowledge of chords (the music's harmonic building blocks). And Walton writes: in his ability to concoct an instant jazz standard, such as "Bolivia" or the more recent "Firm Roots," he has grabbed the baton from the great jazz tunesmith Benny Golson. It doesn't hurt to have those melodies played by saxist Ralph Moore, whose smoky-opal tone and fully developed melodic sense place him among the most gratifying players on the scene. (For more Moore, check the brand-new Who It Is You Are on Savoy--his first new CD in four years.) At 37, Moore has gotten a bit old for "young lion" status; and besides, his musical maturity places him on equal footing with the leader. The quartet includes bassist David Williams and the legendary drummer Billy Higgins, whose dancing, irresistible rhythms--carried along on one of the sizzliest cymbals in music history--allowed him to energize the music of both Ornette Coleman and Thelonious Monk in the early 60s. Higgins has played in this band for nearly 20 years, ever since Walton came up with the name Eastern Rebellion, which I find somewhat misleading. Rather than foment rebellion, they maintain and exhibit the classic values--well-crafted composition, brawny improvisation, and imperturbable swing--that have marked mainstream jazz since the 1950s. Friday through Sunday, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4846.