Programmable LED light systems that react to music and sound are a dime a dozen, all that’s needed are addressable LEDs and a controller. That said, it can be tricky to get larger strips to sync up together, but it’s still not an impossible endeavor. There are some great LED projects; however, that is impressive, to say the least, and German-based programmer Gerrit Gazic's muRLI is one of them.
muRLI is short for (mu)sic (R)eactive (Li)ght system and is a wireless connected mesh of LED nodes, which respond to music and sound. What’s more, it uses programmable EEPROM scripted ROM cartridges that influence the light patterns produced by the muRLI. The platform uses the muRLI as a base station, which sends programmable LED light patterns through WebSockets to connected nodes outfitted with WS2812B LEDs.
Gazic designed the muRLI around a Wemos D1 Mini board that's set up with a Wi-Fi network, and depending on the distance, the nodes can either connect directly to the muRLI, or each other. A MAX4466 microphone in the base station is employed to pick up music or sound and then analyzed for volume and audio, which is displayed on an embedded OLED screen packed within a 3D-printed housing.