(GREAT BARRINGTON, Mass.) – St. Luke’s Chamber Ensemble will perform works by Bach, Mozart, and Vivaldi’s “Four Seasons” at the Mahaiwe on Saturday, September 27, 2014, at 7:30pm, in a presentation by Berkshire Bach. The exact works to be performed are Divertimento in D Major, K. 136 by Mozart; Orchestral Suite No. 2 in B…