Heidsieck’s role in establishing sound poetry in France is significant; his use of tape-recording was especially innovative. His key professional friendship was with Chopin; they were founder members of the mixed-media group ‘Domaine Poétique’. Giorno was also a friend (he helped Heidsieck record the sound of his bank’s computers), Rivers (on sax) his sole collaborator, Schneemann among many visitors. He sent a ‘sound-letter’ to Gysin, ill in London. Ashbery took him to supper with Saint Phalle and Tinguely, who grilled meat on a kinetic sculpture. A banker by day, one of his friends described him as a disciplined anarchist.