lost platlist

I had built a new computer and put itunes 11 on. I had made a backup to external drive from my old system. The new itunes update wiped my playlist. I tried to restore my back up I made and it brings folders and things but no songs. Is there a way, there should be, to transfer everything from my ipod to itunes. Any help would be great TY . tried all the help dicussions nothing worked.