How do I put a song on my iTouch in my iTunes Library?

[Firegecko]

So I bought a song off of iTunes on my iTouch. I want to add this song to the iTunes library on my laptop, but I can't figure out how, because apparently it just HAS to be as complicated as possible. Can somebody PLEASE tell me how I can put this song on my computer? If it helps, I am using a Macbook Pro laptop.

 

[NotABelieber]

Plug your device in, open iTunes, go to File > Devices > Transfer Purchases

For future purchases to automatically download to your laptop, to go Edit > Preferences > Store and you can check whichever boxes you want for automatic downloads.