Another point to consider: Let's say a CD weighs half an ounce, or, roughly 30 CDs per pound. 10,000 CDs would weigh over 330 lbs (feel free to correct me). Storing and transferring 330 lbs of CDs -and- keeping them in good condition, -and- justifying that if you've already ripped them to MP3 seems like a pain in the ass, especially over 20, 30, 40, or 50 years. And on the same note, ripping 10,000 CDs or even a portion of that would take weeks. And that's assuming CDs are still relevant in 20 years.

So if you're like my and consider CDs to be unreasonable, what other options do we have? If I have kids someday, I would certainly want to be able to pass down my music collection.

And, for the last point: What happens to our licenses if/when Amazon or Apple cease to exist?

(Side note: I'm comparing 10k CDs to 10k Books, because 10k Songs is vastly smaller than 10k Books.)