This work was commissioned by Peng Yu of the Shanghai Conservatory of Music, for her to play with the Austrian/Czech pianist Wolfgang Mastnak, a professor in Shanghai as well as at the Munich Hochschule. They performed it in the Great Hall of the Conservatory in September 2010, with an audience of about 350. There is a possibility of a further performance in Germany in 2012.

Shanghai is the most European of Chinese cities, and although Peng Yu’s original expectation was for a piece for piano and western percussion, the possibility of bridging the two sound worlds and cultural traditions seemed more interesting. There are surprisingly few works for piano and percussion duo (the only one by a major composer being Birtwistle’s The Axe Manual), and even fewer for piano and Chinese percussion which tend to be arrangements of Chinese traditional songs, rather than original compositions.

Considering the ‘West-östliche Divan’ nature of the project, it was decided to use the trigrams that form the basis of the ancient Chinese Book of Changes, the I CHING (YIJING), to create the structures of the composition. Hesse used the same text in another ‘West-östliche Divan’ work, Das Glasperlenspiel. The result is a set of ternary forms, rounded off by a binary finale. Throughout the work the percussion represents the Yang lines of the trigrams and the piano the Yin lines so that in each movement, one or other instrument must dominate, and it is only in the finale that an equilibrium between the players is established. The order of the movements is not specified; players are invited to use the ancient method of dividing yarrow stalks to determine the order of performance. However, the final movement is fixed, albeit with an opening improvised section, so the work as a whole balances an eastern indeterminacy with western ideas of structure.