There is perhaps no better ensemble with which to showcase the 20th anniversary of Eastman School of Music's OSSIA New Music group than the JACK Quartet. Founded at Eastman, the quartet will perform in Kodak Hall on Wednesday. Original members Christopher Otto (violin) and John Pickford Richards (viola) and new additions cellist Jay Campbell and violinist Austin Wulliman will perform two contemporary classical stunners alongside students in OSSIA and Musica Nova. The concert opener is the enigmatic and ethereal "String Quartet and Orchestra" by Morton Feldman (an influential 20th century composer with strong Western New York ties), and the program concludes with Steve Reich's mesmerizing "Triple Quartet." Helmut Lachenmann's "Zwei Gefühle" — complete with words by Leonardo da Vinci — is sandwiched in between.