iPod 4

[user-removed]

 I uploaded music to my ipod via wifi, why can't I take it with me and listen to it?  none of the songs will play. it shows the bar moving, but no sound and nothing  through the ear buds. do I have to be in a wifi zone to listen? I had previously had itunes songs from cd's that I own on the ipod, but when I started to sync spotify it said to empty ipod first. so I did, it was completely empty and there's no other apps being used. I have friends who upload and listen in the car.

[MichaelJerzak]

ok, and then have the Spotify App downloaded on the iPod and go to Local Files and sync them to your Spotify app.