For this experiment I used the sound visualizer nodes form the animation nodes addon I have been asked for tutorials a lot lately and so I added a view screenshots and descriptions to explain how I achieved the effect.
as usual you can download the blend file here
please add a comment if you like this longer format posts or if you have suggestions for future posts.
the song I used for the animation is called "The Long Dawn - Part II" and can be found on soundcloud
To analyze the audio material you need a "Sound Bake" and a "Evaluate Sound" node. I also created a copy of the default cube for each bar I wanted in my animation using an "Object Instancer". The strenghts list and the object list are fed to a loop.
This loop is where the magic happens. I used an "Object Transform" node to distribute the cubes along the x axis and used the strength to influence the object scale and the z-location of the cubes.
The index of the loop also affects the hue-value of the vertex color. This color can be used in the cycles material.
This is the node setup of the cycles material. The vertex color can be imported using an "Attribute" node. The attribute we are looking for is "Col". For this animation the vertex color is feed to an emission-shader and a diffuse-shader.
Finally I used a "Glare" Node in the compositor to add a glow effect and a "Lens Distortion" node to prevent the image to look too perfect
Animation Node experiment - polar coordinates
Animation Node experiment - closed curve
Animation Node experiment - cube grid
Animation Node experiment - script node spiral