The first reference to 4'33" came about in a talk that Cage gave at Vassar College in 1947 or 1948. It was part of an interdisciplinary conference, coming at the time when he was beginning his study of oriental philosophy. He said that there ought to be a piece that had no sounds in it. 12 Although the germ of an idea was there, it would be five years before he would actually write it. The next year Cage wrote that he wanted to "compose a piece of uninterrupted silence and sell it to Muzak Co. It will be three or four and a half minutes in length -- those being the standard lengths of 'canned music' -- and its title will be Silent Prayer."13 This statement is particularly interesting in light of what Cage later said about the composition of 4'33", which I will return to shortly.