With an impressive list of artists such as Yes, Rick Wakeman, Keith Emerson, Ian Anderson, Tangerine Dream, Caravan, Soft Machine, Premiata FornerÃa Marconi and many more, the Progressive Rock Trilogy provides the very best of this extensive genre in an organized fashion. This is without a doubt the most important compilation in the history of progressive rock. It is a must have for both novices to this type of music, which is one of the richest within the rock spectrum, and also for informed listeners who will be drawn to the classic hits and artists as well as hard to find gems like the A and B side of the single Ultima Thule by Tangerine Dream.