Sync music from iPod classic to iTunes?
Not officially. Syncing is intended to go in one direction: from iTunes to iPod.
That said, there are some third-party apps that will permit this.
https://tunesgo.wondershare.com/music-transfer/transfer-music-from-ipod-touch-to-computer.html
Good discussion on Apple Support: https://discussions.apple.com/docs/DOC-3991
iMazing has worked really well for me.
https://imazing.com/transfer-all-data-to-any-other-iphone-or-ipad
To add files from iPod classic back to iTunes, go through following steps:
- Connect your iPod to Mac (or PC) and Open iTunes.
- Pick menu "File -> Add to Library..." (or press cmd+o).
- In Open dialogue, navigate to your iPod Classic. It should be displayed as an external drive.
- Select folder iPod_Control/Music and click "Open" button. Note, iPhod_Control folder may be hidden, so turn on showing hidden files on Windows, or use cmd+shift+g combination to open "Go to Folder" input box and just type the name of needed folder (in your case iPod_Control).
- See new files added to your iTunes library. Now, if you have option "Advanced Preferences -> Keep iTunes Media folder organized" turned off - select all newly added files and pick menu "File -> Library -> Consolidate files" for them
All track info is storing inside of music file, so don't care about random names - iTunes will recover track info while opening.
Also, you may want to know about encrypted music files. Tracks that was bought on iTunes and added to iPod will not be recovered in such way - use you Apple ID to get access to them.