Why can't I download music ?

I cannot download any music onto my iphone 5. My restrictions for iTunes is turned "on". I tried downloading straight from my phone and from my computer. When I try from my phone, it says "downloading" for about 5 seconds, then stops, then it doesn't show up in my music. When I try from my computer, it's does the same thing when I drag and drop the songs I want onto my phone. Also I tried automatically downloading EVERYTHING from my iTunes including apps and videos. It downloads ALL of my apps and videos but my music! I have no clue why I can't get music on my phone.