I was inspired by Kitty Yeung's pattern-matching dress, and I wanted to do something clever for my daughter's school dance party. I also had a limited amount of time, and a ready-made dress to use.
After some experimentation, I came up with an old-fashioned VU-Meter display, using the LED modules to colour code the output into a visually appealing, and recognisable display.
I liked the idea of the programmable LED modules, and I was able to get twenty of them in time. I had an Arduino Pro Micro module and a Duinotech microphone module. Because the code is very simple, you could use any Arduino device you have available, and there are many choices for the microphone module. The code also has a "random" mode which means you can do away with the microphone altogether and it looks just as spectacular.
You will also need about 2 metres of soft, flexible hookup wire in multiple colours (advisable, but not essential), two pieces of felt or similar fabric, roughly the width of the dress, a mobile phone "power bank" and a hot glue gun.