The work is scored for three choirs (women's choir, men's choir, and mixed choir), prepared piano, divisi strings, and wind harp. According to the Universal Edition full score, the piano part requires that four pitches be prepared with metal screws and calls for "as large a concert grand as possible" and "amplified". The wind harp is similar to the Aeolian harp, its strings vibrating due to wind passing through the instrument. Manfred Eicher of ECM Records "recorded this 'wind music' on tape and processed it acoustically." The two notes (D and A) performed on the wind harp are to be played on two separate CD or DAT recordings. According to the score preface, the wind harp functions as a drone throughout the piece, fulfilling "a function comparable to that of the ison in Byzantine church music, a repeated note which does not change pitch."