Personally I use the FastLED library a lot using various microcontrollers. There are plenty of "sound reactive" or "audio reactive" or "beat detection" projects

Personally I use the FastLED library a lot using various microcontrollers. There are plenty of "sound reactive" or "audio reactive" or "beat detection" projects if you search the user forum on reddit. You can basically use either a microphone or line level input (depending on if microcontroller has built in DAC, etc). There are plenty of examples/tutorials and code provided. There are also FFT libraries so you can break the audio into multiple frequencies so you can do things like have bass light up red and treble light up blue, etc. You can really do quite a lot with this stuff. https://www.reddit.com/r/FastLED/ https://www.reddit.com/r/FastLED/