When producer Quincy Jones decided to add an organ solo to the title track of Michael Jackson's Bad, he had only one person in mind--jazz organist Jimmy Smith. When Paul Shaffer plays a familiar lick or two on Late Night With David Letterman on his Hammond B-3, Dave will turn and say, "Been listening to Jimmy Smith again, eh Paul?" When Bird or Coltrane wanted to let loose, they'd call Jimmy Smith. Ask Keith Emerson, Rick Wakeman, Patrick Moraz, et al the major influence behind their organ playing and the answer is always the same--Jimmy Smith. Over the past 35 years Smith has not only had a profound impact on virtually every significant jazz and rock keyboardist, but his familiar Hammond organ sound became and remains one of the most widely imitated timbres of popular culture. In an age so filled with synthesizers and samplers, it is always refreshing and exciting to experience Smith's solid showmanship, back-to-basics approach, and unparalleled technique and musicianship. Tonight through Sunday, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4300.