Running iTunes from external hard drive

So I recently moved all my music from my old computer to an external hard drive. Then, on my brother's laptop, I started playing my music on itunes from my external hd. I started putting in a few artists and album artwork.

I'm going to college next year and plan on getting another laptop. Is there a way that I can run iTunes from an external drive? Like when I connect my hd to a different computer can my iTunes stuff like ratings and playlists still appear so that I don't have to organize all over again?