transfering music from pc library to ipad library

I have some albums in my PC itunes library that i would like in my ipad itunes library. I'm pretty sure they are all the albums that i didn't buy through the itunes store, but i remember them being on my ipad library before the update to itunes 12. My PC is still running an older version of itunes (11.4.0.18) as i'm concerned that if i update then i will also lose those albums off my PC library (this is the only place they are currently stored). Is there any way to get the albums across to my ipad (and also to my iphone 5) library?