In my car I have this thing and I don't know what it is. As the music plays in my car the bars move up and down. I think it's called a visualizer? But I'm not sure. My question is though, I'm looking for something simple like that for my mac when my music plays on there. I know there is one on the top of iTunes but it is very small. I'm looking for a visualizer of sorts, whether it be an iTunes plugin or a website. Can anyone help?