Now commonly known by its initials, American Ballet Theatre (or ABT) began its life as Ballet Theatre in 1940. The company enjoyed a close relationship with Jacob’s Pillow early on, with most of its dancers spending the summer of 1941 at the Pillow while officially in a company layoff period (allowing them to receive unemployment checks). They returned to the Pillow in 1947, when the program included Interplay, and then entered into an unprecedented exclusive relationship for the Pillow’s 1949 season, with Ballet Theatre supplying all of the Festival’s ballet presentations. Jerome Robbins had followed his wildly successful first ballet, Fancy Free, with the playful and plotless Interplay. The distinctive costumes were designed by Irene Sharaff, and the original program notes mentioned “a constant play between the classic ballet steps and the contemporary spirit in which they are danced.” To commemorate the centennial of Jerome Robbins, Interplay was revived at the Pillow in 2018.