This is the perfect place on this particular forum. It's an anime-related question and fits right in. That, and I'm a raging-jumping-up-and-down fan of Yoko Kanno. So with a wave of my Magical Princess Wand-O-Power© I declare it "Relevant"!
There are several soundtracks for Cowboy BeBop, not just one disc. Every now and then something "new" comes out. Mind you, it's not all brand-new stuff. There was sooooo much music produced for the show that if you were to pack it all together in one big collection you'd have at leaste nine or ten discs. They (Victor Entertainment) have been slowly releasing the material, perhaps to "keep the fires burning", if you will.
Anyway, here's the discography as best I've been able to assemble...
Original Soundtrack 1
NO DISC / Original Soundtrack 2
BLUE / Original Soundtrack 3
Vitaminless
"Music for Freelance"
(This is an album of remixes by various artists. It's the only one I don't own. I don't mind remixes, but none of them did anything for me.)ASK DNA Mini Album
Knockin on Heavens Door / Future Blues - MOVIE OST
Cowgirl ED OST
(Single that came with the first pressing of Future Blues)Cowboy BeBop CD-Box OST [Limited Edition]
The last one is a huge five disc box set that contains all the tiny bits o' music that didn't make the other OST's. It includes alternate studio takes, remixes done by Kanno herself, live-in-concert tracks (F#¢KIN' AWESOME STUFF!!!), and dialogue recordings by the series director, Shinichiro Watanabe. I'm assuming it's commentary about the show, the music and how they related to each other. I'm not certain as my conversational japanese is severely limited. I'm betting this will be the last gasp, barring any new remixes and/or live material. As best I can tell, they've exhausted all the background music.
A great resource to look up is
The Yoko Kanno Project.
I strongly recommend looking up Yoko Kanno's other works. Her range and variety is staggering. The similarity of one series to another would be like comparing the similarities of a sperm whale and a bowl of petunias.
If you're going to Southern Exposure, stop by the video room before the Cherry Hill Experiment people start running (I'm competing) and I can give more detail and play some of the rare stuff for you. I keep almost every scrap of music she's done on me at all times. (yay mp3's!)
Till then, be seeing you...
Brian T. Price
Malak the Mad