Art Hodes is a historian of conventional stripe: in the early 40s he began writing articles and producing radio programs about the earlier styles of jazz that had influenced him. But hearing him at the piano affords a history lesson, too: his unhurried tempi and unpretentious technique serve the music by opening you to the emotional context of his art--rather than wowing you with showy licks--and it's hard to get too much of that. Of course, it's no news to Chicago jazz followers that Hodes, now in his 80s, remains a splendid practitioner of now-ancient jazz and timeless blues piano. (After all, he grew up and came to notice here in the 20s, and he played regularly around town after returning here in the 50s up until the last couple years.) But for this gig, note the band: it's a quintet, a modern rarity for Hodes (who usually performs solo or with just a bassist). Trumpeter Bobby Lewis and saxist Franz Jackson are both capable of folding themselves into the graceful unity of Hodes's music; with any luck, they may well re-create the delightful small group sessions Hodes produced nearly 50 years ago. Saturday, 8 PM, Green Mill, 4802 N. Broadway; 878-5552.