Hello Leewilljr,
Thanks for using Apple Support Communities.
I understand from your post that when you're trying to sync your music from iTunes to your iPod nano it is not syncing anything. To help get this issue resolved I suggest that you essentially remove the content from the iPod, and then sync it all back from iTunes.
Before we begin troubleshooting, I would make sure that all of your purchased content from iTunes is located in your iTunes library. Use the following article to make sure all of your past purchases have been downloaded.
Download your past purchases - Apple Support
You mentioned that some of your music is not syncing. Is this music that was purchased from iTunes or added to your iTunes library from a CD or other source? If the music that is not syncing was added from a source other than iTunes, make sure that music is able to be played in iTunes. If it will not play in iTunes, follow the instructions in the next article to correct the situation.
If your music is missing from iTunes - Apple Support
Once all of your music is in your iTunes library and is playing as expected, we’ll begin troubleshooting the sync issue.
To begin troubleshooting, I would suggest removing all music from your iPod nano completely using iTunes. This will give us a blank slate to work with so we can sync your content back to your iPod fresh.
1. Connect your iPod to iTunes and select it
2. Select Music under Settings in the left hand side of iTunes
3. Remove the check from Sync Music (You will get a warning that all music will be removed. You are okay to proceed)
4. Select Apply in the lower right corner of iTunes to apply the changes
5. After the sync finishes, verify on your iPod that all music has been removed
Once all of the music has been removed from the iPod, we’ll go back through the syncing process to move your music and playlists back to the iPod.
1. You are probably still on the Music pane in iTunes, but if not, follow steps 1-2 in the previous instructions to return
2. Check the box next to Sync Music and make your selections for music and playlists that you would like added to your iPod
3. Select Apply in the lower right corner of iTunes to apply the changes
Sync your iPhone, iPad, or iPod touch with iTunes using USB - Apple Support
Take care.
