The magic here is that the side length title track works. While there are distinct sections, each with its own character, they are merely individual parts of the greater whole. It flows effortlessly from one section to the next, moving from rock to mysticism to pipe organ, baroque rock and back to the start in a single, unified fashion. It feels like a single composition rather than a series of tunes tacked together like Topographic Oceans. Every member of the band contributes incredible creativity and virtuosity. There’s all the usual prog elements such as weird time signatures, crazy scales, manic playing, opaque lyrics, the latest electronic gadgets and of course the Hammond and Mellotron, and yet it works; like a great symphony works.
Side two opens with And You And I, a beautiful tune that opens with multi-tracked acoustic guitars augmented with some magic electronic keyboards, moving eventually into a slow rock and then into a most majestic, almost pompous slow symphonic section featuring the mellotron and big echoed pedal steel guitar before crumbling back to the acoustic guitars and starting over. The closing track, Siberian Khatru, is basically a rock track featuring strong bass, guitars and vocals. It still manages to include all the usual Yes prog signatures but never dwelling.
This album was a defining moment for Yes as a band and for the whole progressive rock genre.