The neopixels are a cool electronic device. You have a number of leds that are addressable individually and you can set the color you want.
What I am showing you here is a set of neopixels that are connected to an esp8266. The esp8266 is a microchip with a full TCP/IP stack and wifi hardware. The code running on it listens for upd packets at a specific port. The payload on those packets contain the pixel number and the RGB color. The microchip reads packets and sets the neopixels as necessary.
The way I have setup up (under my monitor) is already pretty useful since gives me a lot of light for when I am writing. But someone took it to the next level. Check out this project. The software there is what I am using for this demo. You have the firmware for the esp8266 and also python code that listens to sounds in your microphones, processes it and sends packets to the esp8266 to change the pixel colors based on the sound.
Here is the longer version of the video above: