For listeners who revel in progressive and classic rock (ELP, Yes, Doors, Santana, Tull, Beatles), this is as essential an album as "Brain Salad Surgery" or "Abbey Road."  Please keep in mind that I only refer to the "Spaceship Earth" section of this re-release 2-album CD.  In that glorious album, the talents of this band are magnified by the superlative writing and playing of guitarist Robert Yeazel- yes, keyboard whiz Jerry Corbetta was the leader/founder of the band, but Yeazel was to Sugarloaf as Steve Hackett was to Genesis- an integral composer whose writing inspired the group to realize an intense musical potential- just listen to the album and see for yourself!  "Spaceship Earth" belongs on the same shelf as all the greatest classic and progressive rock albums.  This is a must-buy that will truly please lovers of real music.  Enjoy!