Building off the success (in more ways than one) of A Farewell To Kings, Rush would take the prog-rock concept just about as far as they could with Hemispheres.
Before we continue the story of our wayward star traveler last seen in 'Cygnus X-1 Book I', we are introduced to the concept of Book II, concerning the battle between reason and passion (inspired loosely by Frederick Nietzsche's The Birth of Tragedy), as represented by Apollo and Dionysus; a struggle that gives mortals no peace, and threatens to tear humanity apart. Halfway through the song, our traveler arrives, drawing the attention of both the mortals and the gods in the process. In the end, it is he who brings balance to the dual nature of humanity.
Next, we get the album's shortest song, 'Circumstances' - a perfectly fine song, but compared to the rest of the album it doesn't stand out overly much. Following that is 'The Trees', which at first glance looks like Neil Peart has once again looked to Ayn Rand for inspiration, but in actuality, Peart was inspired by a comic strip which light-heartedly dealt with trees arguing as people do.
The album concludes with 'La Villa Strangiato', the bands first stand-alone instrumental piece, and one of their most complex musical compositions ever. Inspired by a dream that Alex Lifeson, the 9 1/2 minute instrumental is subtitled 'An Exercise in Self-Indulgence', which may be a bit of a return volley against the music 'journalists' who were giving the band no small amount of flack at the time.
Overall, this is another very strong album. 'Hemispheres' shows yet again that the band can do extended pieces very well, 'The Trees' showcases some masterful musical arrangements, and 'La Villa Strangiato' is, without question, a virtuoso musical tour de force. This would be the last of the truly prog-rock albums for the band; they had done what they wanted to in the progressive style, and would decide to switch gears and move forward in a new direction...