Just three notes from the terrific alto saxophonist Jackie McLean and my mind flashes "The Sound" (my personal nickname for him). His tone grabs the ear with an almost magnetic force; it's the sonic equivalent of moire fabric, a complex and layered design shimmering under the ear's scrutiny. McLean's tone enhances his vocal-inflected phrasing, which in turn helps determine his often striking note choices; the resultant improvisations, which incorporate both hard-bop and free-jazz elements, make McLean arguably the most important altoist to find his own voice while expanding on the innovations of Charlie Parker. The ads claim this is his first Chicago date in a decade, but it seems like longer. McLean, a forceful and even ferocious player, drastically curtailed his performance schedule in the 80s to devote himself to teaching, and soon began to gather the mantle of legendry; a series of new recordings (on the Triloka label) shows he wears it well. His group includes his reedman son Rene, whose own recent album (In African Eyes, also on Triloka) successfully blends jazz with South African pop musican exoticism that fits McLean pere as well, and which will likely find a place in next week's performances. Tuesday through next Sunday, May 23, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4846.