MAYFEST, Cornell’s 8th annual international chamber music festival.  Program 4--All Mozart, with a pre-concert talk by Neal Zaslaw at 7:15 pm:  Divertimento in B-flat Major, K. 138 (Chiaroscuro Quartet); Piano Concerto in A Major, K. 414 (Bilson, Chiaroscuro Quartet); Duo for Violin and Viola in G Major, K. 423 (Ibragimova, Quiggle); Mozart: Clarinet Quintet in A Major, K. 581 (Halevi, Chiaroscuro Quartet).  Admission: $20 adult; $10 student; festival pass $120.