'Krystallen', for flute and piano, was written in 1973 for the flautist, Susan Milan, who gave the first performance on BBC Radio 3 with Clifford Benson in January 1975.

The music is in three sections, the last of which isavaried repeat, with palindromic elements, of the opening. These outer sections are texturally three-part inventions, consisting of gently interweaving, equal-voiced polyphony while, in the central passage, individual figuresareisolated and exchanged by both instruments.