Tried a few different tunes, found Violence by Andy Stott to be the most interesting due to the intense dynamics of the track: http://i.imgur.com/YYFBxBN.png

A little more feedback:

- It bothers me that I can't make the bars completely square (the most square setting has a slight roundness to it).

- Maybe an option for designing a custom palette would be interesting. Maybe importing one from http://www.colourlovers.com/ or a similar service could be an option.

- A free download as desktop background option would be a nice touch. Free advertising.