This album is a fan-favorite, and it's not hard to see why.  It's totally not for the casual listener, as it's only 4 tracks, with one track being nearly 20 minutes long and another being 10 minutes.  Continuing the "classic" period of Rush, Hemispheres continues the amazing showcase of superior musicianship, rapid time changes, and crazy drumming of Rush.

The album begins with Cygnus X-1 Book II, which I guess would be a continuation of where Cygnus X-1 left off on the previous album.  They're only slightly related, though.  The song begins with a huge power chord and instrumental introduction, that in my opinion, is one of the best parts of the album.  The first 3 minutes of this song are just phenomenal.  Lyrically, Cygnus X-1 Book II alludes to Greek Mythology, telling the story of humankind, first trying to find the meaning of life by turning to the god Apollo, who tells them that the most important thing is knowledge and logic, and then after finding that unsatisfactory, turning to Dionysus, who tells them that love is the answer.  This doesn't work, either, and leads to a war between the two factions of people that believe in either of the god's causes, and eventually, the man in the spaceship from Cygnus X-1 somehow reaches Olympus from the black hole and becomes Cygnus, the god of balance, and unites everything into one "perfect sphere" from the two hemispheres of logic and emotion.  Conceptually and lyrically, this is some of Peart's best work yet, but musically, it drags on a bit too long.  The opening 3 minutes of this track and the final 7 minutes are great, especially playing parts of Cygnus X-1 on what sounds like a distorted radio.

Side 2 begins with Circumstances, a fairly straight-forward rocker about the catchphrase "The more things change, the more they stay the same".  This is a great track, and the musicianship is as tight as ever here, and is one of the more accessible Rush songs.  However, I usually do end up skipping this one, because of the phenomenal tracks after.

Then comes The Trees, which is a concert staple.  This is undisputably one of the best Rush songs ever, with some of the most clever lyrics that Peart has ever written for the band.  Lyrically, it talks of a conflict with the maples and the oaks in a forest as a parallel with the issue of government and its relationship with the citizens, and how each side misinterprets the other all the time.  But the lyrics are vague enough that they can be interpreted in a multitude of ways.  The usage of the minimoog continues here to great effect, and this is also a mood masterpiece, with the soaring guitar and the minimoog combined to really give off the feel of a forest throughout the song.  A classic in every sense of the word.

And then comes the final track of the album, La Villa Strangiato, which is also one of the best Rush compositions ever, and another concert staple.  It's a near 10-minute instrumental piece that is just a phenomenal showcase of the band's abilities, having time changes all over the place at rapid speeds.  Peart, Lee, and Lifeson are all in top form here.  The drumming is incredibly complex and intricate, almost to the point of inhuman, and if there ever any doubt that Peart is a drumming god, this song will remove any of it.  La Villa Strangiato also manages to incorporate a little tribute to jazz in the final half of the song(actually, starting around 5:48), with Lifeson riffing out a classic jazz melody and Peart even drumming in jazz style.  This is an absolute classic track, and is required listening for every musician, rock 'n roll oriented or not.

Overall, another classic album, and a must-get for any prog or Rush fan.