UPCOMING LOCRIAN SEASON * World Premiere ** American Premiere *** New York Premiere   Saturday, May 31 at 8 PM:           Henri Pousseur   Minima Sinfonia*   Yehudi Wyner   Madrigal***   Louis Andriessen   Xenia   Bill Douglas   Celebration IV   Christian Carey   Butterfly Flourish*   10th Floor Performance Space, Riverside Church           Saturday, August 23 at 8 PM:           Charles Wuorinen   Josquiniana   Charles Wuorinen   Duo Sonata***   Hayes Biggs   Sultry Air, Balmy Breezes*   Louis Andriessen   ...miserere...**   10th Floor Performance Space, Riverside Church         To reach Riverside Church by subway, take the 1 or 9 train to 116th street. By bus, take the M4 or M104 to Broadway and 120th Street. Enter Riverside Church at 91 Claremont Avenue (one block west of Broadway, between 120th and 122nd streets). Parking is available at the Riverside Church garage, located at 120th Street and Riverside Drive. For further information contact John Kreckler at (718) 458-4864.