Songs on ipod shuffle got deleted while charging on pc.

Your iPod might have been automatically synced with your iTunes. If you connect your iPod on a PC and your iTunes is set to Auto Sync, it will sync all the content of your iTunes library to your iPod. If the iTunes library is empty, then it will cause to deletion of files on your iPod. Also, your iPod might have been synced to a different computer before you plug it to yours. Might as well select the Manually manage music and videos when organizing your iPod.

 

If you do not have a back up of your iPod's content, you can use a software to retrieve deleted songs:

 

Stellar iPod Data Recovery – https://www.recovery-android.com/recover-files-on-ipad.html

Recover My iPod – http://www.recovermyipod.com/