I have my iTunes account logged on to two Macs (one Macbook Pro and one Macbook Air) and want to get all my purchased music on both. How do I go about doing this?

I have a personal Macbook Pro, which I have had for a very long time. My iTunes account has a lot of music from CD's but also has a lot of purchased music. I also have a Macbook Air for work and have purchased a lot of music on this computer using the same iTunes account. Is there a way to get the music to show up on both computers being that they are from the same account?