well...28 gigs of (mostly) MP3s on HD...thats 4-5 thousand, I guess...(half of them Child Ballad versions)(and Everything from Tennesee Ernie to Mahalia Jackson)....and several thousand more RealAudio files on CD disks of Rose, the Record Lady's Country Music archives (acquired before she made them so you had to get one at a time)....
add in about 600 LPs and a small collection of commercial CDs (I'm poor) and I suppose I could not play them all easily in my lifetime.

and Clinton....I 'think' that the application you might want is an Explorer substitute called TrackerV3. (free for home use) It has an amazing array of tricks related to file management. The guy who wrote it posts regularly at the alt.comp.freeware newsgroup, and often answers questions there.