I know that on iTunes, if you press ctrl + T, you open up a music visualizer. However, it only works, to the extent of my knowledge, on purchased songs. A music visualizer would be an extremely impressive addition, and it would be extremely amazing. Just an idea, but if it was implemented, then I think that Spotify would be about 50x better.
A Visualizer for Spotify has already been suggested.
Please add your kudos and comments there instead. 🙂