When explaining the difference between modern and post-modern art, philosophers have often emphasized the difference between the process of artistic creation and its final product. For post-modern artists, developing a new creative process is often as important as the aesthetic considerations of the resulting product. John Cage's Branches amply demonstrates the distinction in priorities. In this piece, Cage stipulates that musicians are to use one of several pod rattles from the Mexican ponciana tree and a number of cacti. Once the instruments have been rounded up, the spines are plucked and amplified with a simple record player cartridge. The song duration of eight minutes is divided by the player according to an I-Ching cast, which is also the preferred method for instrument allocation, each instrument appearing in only one part. "Using a stopwatch," Cage states, "the soloist improvises, clarifying the time structure by means of the instruments. This improvisation is the performance." Metal and animal-based instruments are strictly prohibited. Essentially, Cage is creating a series of barriers for musicians to creatively overcome. To the casual observer, there's nothing extraordinary about the minimalist composition. However, there is something quite extraordinary about seven musicians gathering together using thistles, seed pods, and blocks of wood to record music inside a room within a dam at a constant 6 degrees centigrade. Thus, process versus product.