The web link for Eno's cards is below. These cards were published in the 1970s as a tool for developing pieces of music. When a stalemate in composition or recording is met a card is drawn and its instructions followed. A similar deck could be created and followed in the composition and performance of a piece of music. (The writer Italo Calvino used a Tarot deck to write 'The Castle of Crossed Destinies'.)