I keep my music separately on an external hd and only transfer Cd's I want on my iphone at a particular moment. I would NEVER keep my only copy of my music library on iTunes. ITunes has been known to really screw up my library in the past. Apple can makes it extremely difficult to work with your music. Plus, I just have too much to keep on a computer's hd..NOT SAFE. I've made hundreds of data DVDs (which can hold about 25 Cd's on one disc) and then, of course, have an "active" copy of my library on an external drive that I can listen from or copy to itunes or whatever.
On a side note, I find it funny that everybody measures their music in songs. I've always measured mine in albums..lol..I dont have one single individual song that is NOT on a complete album. That in itself is a sign of the times, I guess. The music today is so completely devoid of soul and creative inspiration that it's only worth buying a single song..lol j/k, of course. ...I'm old