copy from ipod nano to windows 10

Without a tool? You can't.

iTunes is not designed to move music from the iPod to iTunes.

However, have you looked in your computer's recycle bin, for the deleted music? If the music is in there, restore it to its original location. Alternatively, have you ever made a backup of your music, that you could use to recover your music, or at least some of it.

See Recover media from an iPod - Apple Community. If you can explore the device in disk mode then iTunes and Windows Explorer may be all you need.

tt2

You're welcome. 🙂

See Backup your iTunes for Windows library with SyncToy - Apple Community.

tt2

Try https://www.wikihow.com/Put-an-iPod-Into-Disk-Mode to get your device into disk mode. The link I posted earlier should explain how to recover the media files once that is done.

tt2