Short of Hugh Hefner, you'd be hard-pressed to find a more restless, experimental senior citizen than Lee Konitz. At 78, the saxophone giant is a year younger than his fellow Chicago scion but arguably more vital and relevant. His albums in the past decade have included a recording of multitracked solo numbers, a symphony date and a trio set with Brad Mehldau and Charlie Haden. Konitz hews to the latter format for his appearance at the Folly, setting his alto sax alongside Rufus Reid's bass and Joe Farnsworth's drums. Lending marquee value is Bill Frisell, whose shimmering guitar playing conveys stillness and friction with equal expressiveness. Both men transcend whatever jazz idiom their instruments land on; just call them contemporary. Between them, Konitz and Frisell have played with the most familiar names of jazz past and present, but the two have recorded only a couple of songs together, so Saturday's bill is not to be missed. A 7 p.m. talk with the musicians precedes the gig.