Despite releasing only one LP, the United States of America was among the most revolutionary bands of the late '60s -- grounded equally in psychedelia and the avant-garde, their music eschewed guitars in favor of strings, keyboards and haunting electronics, predating the ambient pop of the modern era by several decades. Leader Joseph Byrd had studied with contemporary classical composers including John Cage (together with Yoko Ono); after the USA's single record he went on to form the equally short-lived "Joe Byrd and the Field Hippies"