John Cage (1912-1992), one of the most experimental and influential musicians and visual artists of the 20th century, became interested in Eastern philosophies, especially Zen, during the 1940s. He began applying principles of chance to both his musical and his visual art. E.1487 and 1488-1984 are two dry-point engravings from a suite made following a trip to the Ryoanji Rock Garden in Kyoto, Japan, in the early 1980s. This garden, according to the classic travel guide Nagel, 'represents the quintessence of the Zen doctrine and the art which it fostered'. Cage used 15 rocks from a group of 16 collected from different parts of the world and drew around each of them onto the copper plate with a dry-point needle in various positions determined by chance operations dictated by the I Ching ('Book of Changes'), the ancient Chinese book of divination. The letter 'R' in the title stands for the number of rocks used in making each image. For 2R =13.14 he drew round two rocks 15 times each and 13 rocks 14 times each.