It’s a powerhouse combination at the Ravinia Festival: Patti LuPone, Audra McDonald, Michael Cerveris, John Mahoney and Stephen Sondheim, with a dozen or more Tony Awards between the five of ’em. LuPone, McDonald, Mahoney and Cerveris star this weekend only (Aug. 26-27) in the Ravinia’s concert staging of Anyone Can Whistle, the legendary 1964 cult musical—about inmates cut loose from the nut house—by Sondheim and another great, gay artist, Arthur Laurents. Sondheim himself, now 75, appears at 7 p.m. Friday (Aug. 26) before the 8 p.m. performance. Saturday is 7:30 p.m. (847) 266-5100; $10 (lawn), $45 & $80 (pavilion).