If I purchase an iPod Touch or shuffle and am not connected to internet to confirm payment to Apple then will the music stop working like it did my iPhone. I am trying to keep my music and be able to listen to while on airplane mode for a long period

While I was aboard a navy vessel for about two months, I was required to keep my plane on airplane mode the entire time, however after the first month my music stopped working. I was unable to listen to any of my songs or videos from ITunes music. I think it my he due to the fact that my phone could not verify payment from apple. Is there anyway that I can put my music on a iPod Touch and not have the same problem. Please keep in mind that I would transferring the music from iTunes on my computer to the iPod. Please let me know if I can do it that way or any other. Thank you very much for the help in advance