Lori Belilove and The Isadora Duncan Dance Company return for an encore performance at Untermyer Gardens, appearing in the exquisite outdoor Amphitheater where, in 1923, Samuel and Minnie Untermyer watched a performance of The Isadorables, the troupe formed by Irma Duncan.   The Company will appear in traditional Duncan repertory along with new choreographies, inspired by the Duncan aesthetic, by Belilove.  Dances are to music by Chopin, Gluck, Grieg, Schubert, John Link, and Mykola Leontovych.  (rain date is Sept. 2 at 5:30 PM)