Cowboy Bebop's soundtrack, as its name suggests, prominently features bebop. Stuff which sounds a bit like U2 will be anomalous.
But it isn't. It's one of the strongest points in the Bebop soundtrack. While it indeed prominently features jazz, and perfectly crafted jazz at that, and in a variety of styles as well, that isn't it's strongest point. It's forté is that it features ALL TEH MUSIC. It's eclectic as all hell, yet everything, everything is perfectly crafted. Not composed, crafted, because it has to musicalize a anime show, yet most of it is awesome music that can be listened to alone and you don't even have to remember you're listening to a soundtrack.
To wit, we have New Orleans-style early jazz, NY-style jazz, all out Bebop like Tank! or Clutch, latin-inspired stuff, piano, harmonica and guitar-driven blues, some of it vocal and my god, such vocals, and even some hard-to-clasify music that has some jazz bits into it that you could use the horrible term of "world music" to describe it.
Yeeet, we also have amazing electronic rock, electronic music, electro-jazz if there is such a thing (yeah, Saint Germain would like to have a chat with me), metal, U2-style stuff, straight-up pop, loads of balads, country, and even an amazing version of Schubbert's Ave Maria. And mind you, we have english, spanish, japanese, italian, french, whatever the hell it is that Green Bird is sung in, and I'm sure I'm forgetting something in here. And all of it sounds so coherent when playing in the albums. It's just mind-blowing.
Cowboy Bebop is the only anime soundtrack I've played complete without people asking if it was a soundtrack to something. It's
that good.