HAPPENIN’ OTSEGO for SUNDAY, OCTOBER 2 Cooperstown Music Festival Presents The American String Quartet MUSIC FESTIVAL – 4 – 6 p.m. The Cooperstown Summer Music Festival presents its last concert of the season featuring the American String Quartet, returning to the festival with acclaimed French cellist Philippe Mueller and Festival Artistic Director, flutist Linda Chesis for a program of works by Joseph Haydn and Aaron Jay Kernis, as well as Schubert’s sublime String Quintet. Tickets, $30/adult. Christ Episcopal Church, 46 River…