Building a Video Synthesizer with Python is an excellent blog post from Make Art With Python.  Although it doesn’t use MicroPython (yet!) the post explores how to use Python on a computer (like a Raspberry Pi) to create a video synthesizer that reacts to sound.  This project highlights some of the benefits of using Python, like easy access to powerful computational libraries and simplicity of coding.  With just a handful of lines of Python code the author ties together the aubio and Pygame libraries to make colorful animations when guitar notes are played.

The same kind of fun artistic creations are possible with MicroPython and CircuitPython too!  For example imagine animating NeoPixels or Dotstar lights based on the beat of music. You could even communicate between Python running on a Raspberry Pi (perhaps performing all the audio processing) and MicroPython or CircuitPython on a tiny board controlling lights and hardware.  The possibilities for making art with MicroPython and CircuitPython are nearly endless!