Say what you will about the Kronos Quartet’s punk-chic posturing: few contemporary-music quartets rival them in adventurousness or vitality. Or in political correctness: a typical program of theirs is more often than not a paragon of multiculturalism. The crowded lineup for their latest Ravinia appearance includes works by composers with names like Maraire, El Din, Nishimura, Sallinen, and Schnitke, all written within the past decade or so. Alfred Schnitke, perhaps the Soviet Union’s most original musical thinker since Shostakovich, is represented by his Quartet no. 2, a succinct tour de force that makes deft use of 16th-century Russian church chants. Echoes From a Play, by Finnish composer Aulis Sallinen, close to Schnitke in age and geography, will receive its world premiere; it’s a self-contained part of an opera-in-progress that deals with the downfall of the Ethiopian dictator Haile Selassie. Also worth mentioning is Soliloquy, by University of Wisconsin alum Scott Johnson, which uses text from a lecture by I.F. Stone. Tuesday, 8 PM, Murray Theatre, Ravinia Festival, Green Bay and Lake Cook Rds., Highland Park; 728-4642.