Because this round is so complex, separate image and sound files are provided for each part. The first two images are for four of the six voices.The first line for four voices:
Superb presentation of this round. And his translation seems right. This is the basis, the bare bones music. The midi instruments are not much, but the point is to listen to the pitch and rhythm and the interplay during the round part rather than to get lost in the immediate sensation of the sound. Platonic idealism, maybe.