There are only three vocal tracks on this CD.  The rest is all instrumental.  That being said, this is an okay CD.  I really don't have enough patience to review each of the instrumental tracks (really, I have a short attention span), so I'll work with the vocals first and then point out some highlights.  "The Crescent Moon Bed" is a very light piece with very airy instrumentals.  The singer's voice is pretty high- probably a first soprano.  It's very bouncy and happy.  "Memory of Time" is one of the best anime songs ever.  It starts out as very empty, almost a-capella, and then instruments gradually come in, I think a couple chimes and strings.  You can't really get as much out of this song unless you've seen the absolutely beautiful animation that goes along with it.  I use this song as a lullaby when I babysit, and it really does help to calm down my shrieking niece.  The last vocal track is, frankly, disturbing.  It would make an interesting instrumental piece, and it would be a good vocal piece, except Hamada Rie, who you may know from Marmalade Boy, is singing it.  There is something about her voice that annoys the crap out of me, and I don't know what it is. 
Now, onto highlights.  Track 2 is the piece played at the very beginning of the first OAV.  It's mostly strings, and lives up to its name, "Nostalgia".  Track 4, "Moon Shadow" reminds me of the music for Final Fantasy IV.  It's mostly harp and woodwind.  Track 10, "Sung Out of Love" is an interesting piece, very ominous sounding at first.  Then it starts to perk up a tad.  Overall it's very depressing.  I can't remember where the next track "Thoughts Overflowing" is from, but it's a very weird BMG that is also very cool.  Track 13 "Departure for Zero" is the preview music.  I never really liked it that much, because of all the synth instruments.  "Tragic Fragrance" is a really sad piano melody from the moon flashbacks (I think).