This is the first paperback edition of Roy Howat's stimulating and provocative study of Debussy's unorthodox use of musical form. Throught detailed analyses of the piano pieces Reflets dans l'eau and L'isle joyeuse and the symphonic poem La mer, Dr Howat shows how the pieces are built precisely and intricately around the two ratios of Golden Section and bisection so that the music is organised in various geometrical patterns which contribute substantially to its expansive and dramatic impact. The final chapter traces evidence of whether the proportional systems were designed consciously, and if so, where and why Debussy might have learnt such techniques. The evidence includes his involvement in the Symbolist movement and in esotericism.