I spent about two hours on the phone with Apple Care.  The music library is still in the computer, and if I go to the hard drive and open the files, I see everything, only it's no longer accessible on the i-Tunes site! However, if I click on a number in the music library icon, it plays on i-Tunes!  Absolutely ridiculous.
 The young man helping me was very nice but he couldn't do much.