My main folder on my PC "Trollheart's Music Centre", which is not the only place I have music stored but is the main one, currently stands at 507 gig, equating to 71,200 files in 6,312 folders. The vast majority of this is downloaded (legally or illegally) over probably 5-8 years, though mostly in the last 3, with my CD collection digitised taking up a mere 6.37 gig, 149 folders, 1,497 files.
There's music spread all over my hard drives though (sounds suggestive!)
with more on external drives and DVDs.