An infinity mirror lit by individually addressable RGB LEDs and controlled by a PIC32 microcontroller. When connected to an audio source or microphone it performs a frequency analysis to visualize the music within the mirror. It features multiple additional pattern modes that can be cycled through using a button input and tuned using three knob adjustments. Relevant information is displayed on an LED screen. Low-level controller code was written in C and generated from scratch (flipping bits to send signals to the lights, reading from sensors, etc).
I used the same technology and scaled it up to automatically animate music on a Christmas tree as well!