less than half my music showed up

[tr.pet...@gmail.com]

I synced my htc evo 4g lte with itunes using notpod. Took me awhile to figure it all out as I'm technologically challenged but did get there eventually. But less than half my music is actually available on my phone. I tried syncing again but notpod seems to think all the music is already on my phone. Any suggestions? All of my daughter's Taylor Swift made it but very little of MY music did!