In its 32st year, the Grant Park tradition brings in living legends and local 12-bar regulars. The theme this year is a tribute to Muddy Waters and Willie Dixon, with Billy Branch, Mud Morgenfield and more leading the charge. That all goes down on Sunday. If you're looking for just one day to attend: Buddy Guy headlines on Saturday at 8pm at the Petrillo Music Shell, after Shemekia Copeland warms up the stage. South Side soul underdog Syl Johnson headlines at the same place and time on Friday, which should be hot. Those with an even looser definition of the blues might want take note of hunky, bruised crooner Hozier, who hits Pritzker Pavilion on June 10.