In Garageband macOS 10.4.6, where is the "Media" section that was in the previous GB version?

Hello, I just updated to the GB macOS 10.4.6, (from previous version) but the "Media" section that had my music from previous "itunes" and "music" are no longer featured on the right hand side of GB. Nor were the "movie" tracks listed either.

Do I have to, or is it possible to go back to the previous version of GB, and then have the "Media", either by going back to my backup and restore to previous version, or is all lost?

Thank you!