How to add an album to your iTunes library on your computer when bought on an iPhone?

Ok, here's the situation. I bought an album on my phone. I want to put it in my library on my computer. So basically, how do I do that? I tried going to the store but it says I need to purchase it again.

Thank you!

Added (1). Oh nevermind I got it…

It'll probably give it to you for free. This happens to me. Just hook up your phone and transfer purchase! Hope this helped and please please answer mine!