Ed Petersen returns, and not a moment too soon. Never at a loss for great tenor men, Chicago has nonetheless missed this virtuoso in the 16 months since he moved to New Orleans. Yes, we've had his second release (The Haint on Delmark). But it's no replacement for his intense and genial presence. On tenor, his main instrument, Petersen's fat and malleable tone pushes the music forward, and his skilled articulation makes him seem to be gobbling up the chords faster than his pianists can dish them out. (He backs off a notch on soprano with a sound recalling the old New Orleans masters and the modernists who popularized the instrument in the 60s.) Petersen's high-energy approach to the sax finds its roots in John Coltrane and such local giants as Von Freeman and Johnny Griffin, whose hyperexpressive balladry has also left its mark. This weekend Petersen plays in two of his favorite contexts at his favorite club, so one might well expect a rousing performance. Next Friday, December 29, 9 PM, he plays with Von Freeman. Next Saturday, December 30, 8 PM, he joins vocalist Kurt Elling (whose career he helped foster). Green Mill, 4802 N. Broadway; 878-5552.