We're using audio analysis, and applying that to control the output of a Generative Adversarial Network (GAN) trained on a particular set of images, which define the visual theme.
My co-founder has a YouTube channel where he will be going into technical detail how this all works. He will be posting a video in the coming weeks. https://www.youtube.com/channel/UCNIkB2IeJ-6AmZv7bQ1oBYg