There are some amazing shaders on ShaderToy that react to audio data. I had a play with Unity to see if I could convert one over, a video of the result is below.
I’ve used a combination of data from the audioclip and spectrum data from the listener to create a texture that gets passed to the shader. The left side of the display shows the texture and the right is the shader from shadertoy (credit to user poljere) : https://www.shadertoy.com/view/MtBGRt.
[Edit] Apologies for the poor quality of the video, I’ll try and get another one up soon!