Here's a basic scene with the sound modifier running. You might have to re-link the sound file in the modifier and also in the special track in the timeline. New to this so wasn't sure how to package it correctly.

You can see that the editor view shows colored particles, but Octane renders them as ...

I was following along with this Grayscalegorilla tutorial on the x-particles sound modifier: http://greyscalegorilla.com/tutorials/animate-using-x-particles-3-5-and-the-sound-modifier/

and I'm really interested in using the "Map Parameter: Color" feature but have no clue how to have that working ...