My computer won't read that I've bought a song, but my phone will. Help?

I bought a song and I'm being asked to put it on someone else's device. Well, the computer won't read that I bought that song. My itunes account and my playlist on my phone recognize that I've bought it, but my laptop treats it as if I haven't even bought it yet. I've synced my phone to my computer multiple times and still no change. Help!