I can't put music on my Iphone 5?

I have an Iphone 5, and I can't put music manually via my computer into my Iphone 5. I try to drag it, but it doesn't work. What can I do? I'm getting a bit frustrated. Please give details, I'm not the best with computers.

Hi, I JUST went thru this putting music on my boyfriend iphone 5 via the computer the other day. It took forever because I kept dragging it and same problem.
You have iTunes on your computer right?
Well assuming you do… You go under the music tab and your songs should appear. You click or right click the song and select add to. It prompted me to make a play list. Once I did this it finally worked, then you have to click sync.
It's frustration but once you get it it works