An early iteration of Chamber Cartel: (back row, from left) Tracy Woodard, Gabriel Monticello, Victor Pons snf Thomas Avery; (front row, from left) Jean Gay, Paul Scanling, Caleb Herron and Amy O'Dell. (Photo by Max Eremine) The ensemble will perform Morton Feldman’s daunting four-hour-plus trio For Philip Guston at Goat Farm on September 27.