Hi,
I have several years of advanced experience in arduino development and 15+ years in electronics/embedded development.
I have worked several times with neopixels (WS2812B controller) in different projects. You can find a standard demo I compiled and uploaded to an Arduino UNO:
[login to view URL]
The video is not very good because of definition and also the brightness of the LEDs... But you can get the picture, I think... I used a neopixel ring because it's what I have handy at the moment, but already worked with neopixel strips (it's all the same, only the physical layout is different).
I only need to attach a microphone and take care of sampling, define the maximum threshold to trigger the "random" feature, update each LED color depending on "random" or "normal" state and I think it's done.
Have you considered the usage of the microphone breakout board with a digital output with adjustable signal trigger threshold ? This would simplify the arduino programming and would make the system more robust, I think... Here's an example board:
[login to view URL]
I'll easily add the requirement to configure (through #define statements) the total number of LEDs and number of LEDs per group.
Please let me know if you are interested and feel free to contact me for additional info.
Best regards,
Carlos.