In the early seventies, King Crimson, Yes, Jethro Tull, Emerson, Lake
and Palmer, and many others brought forth a series of adventurous and
visionary works, often of epic length. Responding both to the new
possibilities in rock music opened up by "Sergeant Pepper's Lonely
Hearts Club Band", as well as to the countercultural politics and
aesthetics of the late sixties, these musicians applied consummate
instrumental and compositional skill to transgressing boundaries. Since
the late seventies, histories of rock music have either ignored or
marginalized the progressive rock era. In part, this has occurred
because rock music criticism has taken an almost completely sociological
turn, with little or no interest in musical form itself. In "Listening
to the Future", Bill Martin argues that it is a musical and political
mistake to ignore this period of tremendous creativity, a period which
still finds resonance in rock music today. He sets the scene for the
emergence of progressive rock (showing that, in fact, there has always
been a progressive trend in rock music, a trend that took a quantum leap
in the late sixties), and develops a terminology for understanding how
an avant-garde could arise out of the sonic and social materials of