"Cataract" means rapids, swift current, or flume. It depicts a small quiet steam gradually increasing its current and velocity as it scrapes away at the earth. The musical characteristic changes as the stream is transformed. Imagine not only the flow of the stream, but also the various scenes surrounding its progress. The sounds of each instrument reflect the stream itself. Envision the many aspects - high and low, loud and soft, large and small - of the stream's flow.
(Yuichi Abe)