Almost 20 years ago, Dave Liebman laid down his tenor saxophone to concentrate solely on the soprano, and to this day he remains one of the three definitive modern voices on that instrument. (Wayne Shorter. Steve Lacy.) Few have been able to find the full range of the soprano, to maintain its sinewy strength while exploiting its fluttery grace, yet Liebman goes even further. He’s completely inside the instrument, and the result is a forceful complexity that no one, with the possible exception of John Coltrane, has been able to match. This year marks the 25th anniversary of Coltrane’s death, and I’d be surprised if that fact went musically unnoticed by Liebman, who has so fully absorbed Coltrane’s expansive vision and used it as a foundation for his own impassioned approach to improvisation. Many musicians act as if brains and passion were mutually exclusive, but Liebman–as Coltrane often did–displays the passion of intellect, understands the emotional excitement of brilliant ideas. Liebman’s Chicago rhythm section does the same, though not uniformly: it balances the sizzling virtuosity of pianist Jim Trompeter and the high energy of Joel Spencer’s drumming with Eric Hochberg’s contemplative and nuanced bass work. Saturday, 8 PM, Green Mill, 4802 N. Broadway; 878-5552.