IPhone unable to download music?

I've had my iphone 5 for about a month now, it's all up to date, and everything works fine, apart for one thing. When I go into iTunes to buy a song, it allows me to buy it, and charges me. Then it pops up in a 'downloading' section, it begins to download, but when it reaches the end, I get a notification saying 'unable to download song' and then options to retry or 'okay'. I have an iPad, and wirelessly it downloads perfectly on that. Any ideas as to what the problem is?

No idea what the problem is, but you can plug the phone into the computer and click manage music manually or something along those lines and download music from a YouTube converter website, or there's alternative apps for downloading free music on the app store. And you might wanna check the problem with the apple people…