Actually, I think that's 15,000 three minute songs, so that unless one only listens to pre-LP era performances, your jazz ipod will hold less songs.
I take great pleasure in going through my CDs and selecting the songs I like best for my itunes library/ipod. Since I only have 5 gbs left, I'm not going to be able to do this much longer, unless they put out a bigger ipod or I start removing songs.
From my point of view, when I'm traveling or driving, the more music I have on the ipod makes for a better experience. I have huge selections of Ellington, Mingus, and Charlie Parker, among others. Do I want to stop adding Ellington for example? I think not. Plus, for variety, I have alot of blues, music from Latin countries, Africa, a little rock. The more music the better.