Music wont show up on my phone ! :(

I'm dragging music on my iPhone 4 and i can see the music in the music section of the dropbar on my iPhone in iTunes but the music wont show up on my phone. Any time i click on the iPod app it says there is no content on this phone please connect to iTunes. But every time I connect it to iTunes i can see that there is music on my phone and I'm syncing and syncing for no use. I'm kinda gettin mad now since ive been trying this for a while and it worked perfectly on my mac that i used before this ****** thing of a PC.