If you are experiencing the lost of certain purchases, you can re-download the purchases from your history:
1. Open iTunes on your computer.
2. If you're not already signed in, choose Store > Sign In, and enter your Apple ID and password.
3. After you've signed in, click on the iTunes Store button located in the upper-right of your iTunes library.
4. From the top navigation bar in the iTunes Store, click on the content type you're looking for (Music, Movies, TV Shows, Apps, or Books).
5. Click Purchased located in the Quick Links section on the resulting page.
6. From your Purchased page, you can click the tab for the content type, if you would like to download other previously purchased items (Music, Movies, TV Shows, Apps, or Books).
7. Click Songs or Albums to change the page view and All or "Not in My Library" to view your purchased content that currently is not downloaded on your computer.
8. Click the download icon to the right of each item to download that item.