Based on Eric Fenby's 1936 memoir 'Delius as I knew him', it traces the last years of Frederick Delius, and Fenby's dedication in giving up five years of his life to helping the blind, paralysed composer set down the unfinished scores he could hear in his head. Perhaps the finest of the series of biographical films that Ken Russell made for the BBC in the Sixties, Song of Summer is an immensely moving story of sacrifice, idealism and musical genius.