Hindemith's succinct instructions in the original score of the 1932 ''Cantata'' (ED 1624, performance repertoire) for part of the ''Plöner Musiktag'' are: ''The three preceding choral pieces are sung together at the same time as the orchestral accompaniment, forming the main chorus of the piece.'' In response to the wishes of many, these instructions have been translated into a separate score as an answer to problems that have sometimes beset performers. Any conductor may now have an overview of all the music that is sounding at any time, and less experienced singers and instrumentalists can be offered assistance if necessary. The instrumentation is flexible and can be adapted to suit the forces available.