Hello gslrobgsl,
Thanks for reaching out to us about this issue. If a content you are trying to view or use is requiring you to update your iTunes, then we would recommend proceeding with the iTunes update.
We do understand your concern about your iTunes library. Before installing the iTunes update, we recommend backing up your iTunes library.
If you are using a PC, use this resource as a guidiance to back up your iTunes library: Back up and restore your iTunes library on your PC
If you are using a Mac, use this resource as a guidance to back up: Back up your Mac
Thank you!