In jazz, the rhythm section forms the heart of almost every ensemble, and the communication between rhythm section and leader largely determines the music's success. So when the rhythm section is the leader--as with TanaReid, the two-saxophone quintet assembled by drummer Akira Tana and bassist Rufus Reid--you've got it made in the shade. One of the more versatile modern drummers, Tana has danced his sprightly, athletic rhythms across dozens of recordings in recent years, and Reid practically defines modern bass playing: musically, he's a direct descendant of Ray Brown in his ability to emphasize a large tone, balletic facility, and superlative musicality in equal balance. It doesn't hurt that the remaining member of the rhythm section, the expansive and sometimes spiky pianist Rob Schneiderman, has led two terrific albums of his own (on the Reservoir label). Reid and Tana have used so inviting a backdrop to lure two of New York's fiery young saxists, who reflect the leaders' energy as well as heir historical perspective, into the formidable outfit; this week they've also lured Kenny Burrell, who in the 50s helped gain wide acceptance for the electric guitar as a jazz instrument, and who will join in the second half of TanaReid's sets (but not on Sunday). Tuesday through next Sunday, May 24, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4846.