National Theatre, 1321 E Street Realty Corporation, lessee, Louis A. Lotito, managing director, Ballet Theatre Foundation, Blevins Davis, president presents "Ballet Theatre," Lucia Chase and Oliver Smith, directors, Alicia Alonso, Igor Youskevitch, John Kriza, Mary Ellen Moylan, Gemze de Lappe, Paula Lloyd, Ruth Ann Koesun, Eric Braun, Lillian Lanese, Michael Lland, Anna Cheselka, Jenny Workman, Kelly Brown, Dorothy Scott, Liane Plane, conductor Joseph Levine, regisseur Dimitri Romanoff, assistant conductor Otto Frohn, ballet master Edward Caton. "Interplay," ballet by Jerome Robbins, music by Morton Gould, scenery by Oliver Smith, costumes by Irene Sharaff, piano solo: Edmund Horn, conductor: Joseph Levine.