itunes library

I had a nano all set up in my itunes. I just got an itouch and wanted to set up a separate library for it and followed instructions that were given on this forum. All seemed right, except I now see that only 53 of my 600 songs are on the itouch library.
Can anybody give me some help in having all of my music available on both the nano library and itouch library? If not, how can i just get all of my music back onto to the itouch as I will primarily be using that device.

Thanks for any help