1. Open iTunes on your computer.
2. In the menu bar at the top of the iTunes window, click on "Account" and then select "Sign In."
3. Enter your Apple ID and password and click on "Sign In."
4. Once you are signed in, click on the "Store" menu and select "Authorize This Computer."
5. Enter your Apple ID and password again and click on "Authorize."
6. Now, open the "Music" section of iTunes. Under Music, you should see any music that was downloaded directly from iTunes.
7. Select the music that you want to download and click on the "Download" button.
8. The selected music will now be downloaded to your computer.
By following these steps, you can retrieve the music downloaded directly from iTunes on your iPod Touch, even if you have lost the iPod itself.