Every so often, I get CDs that become part of my "desert island collection."  You know, the albums that you absolutely would need to listen to if you were trapped on a desert island.  There is just so much to listen to on this CD, but also so much to to learn.  This album's best qualities are its lyrics.  The basic theme of the album is about opening up and looking at things a different way, and after listening to this CD, you may very well listen to modern rock music in a different way.  Complex rhythms, subtle yet powerful guitar playing, and vocals that somehow soar over all the monstrous sounds below.  Tool's song structure is also something worth mentioning.  I've never seen a band capable of playing one riff so many different ways and exploring which ways it can go.  Forty-six and 2 is basically the same riff over and over again, but it gradually changes, and by the time the song ends, you realize that its still the same riff, just another possibility for it.  But anyway, this is a superb album, a must for anyone who wants to learn something new from a rock CD.  It captures every mood and will leave you spellbound.