It's heartening to see the New York New Music Ensemble, arguably the most skillful and persuasive contemporary music group around, visting the city on a regular basis. Better yet, for the third time in as many years, it plays Ravinia as part of the festival's effort to introduce new works to conservative-minded North Shore audiences. At this concert the ensemble will perform a brand-new chamber composition by Jacob Druckman, the distinguished elder statesman of American music who recently made the news after the Met canceled his opera commission (Met officials say it was too late, other suspect politics). However, Druckman successfully completed the jointly commissioned Come Round, sponsored by Ravinia and two other summer festivals, which premieres tonight with the ensemble's talented clarinetist Jean Kopperud and flutist Jayn Rosenfeld in the spotlight. The postminimalist Undertones, by Australian Michael Smetanin, also makes it local debut. Two modern classics, Bartok's virtuosic Contrasts and George Crumb's eerie, mystical Voice of the Whale, and Elliot Carter's obtuse Con Leggerezza Pensosa round out the program. Robert Black conducts. Tuesday, 8 PM, Bennett Hall, Ravinia Festival, Green Bay and Lake Cook Roads, Highland Park; 728-4642.