Do you adore LEDS? And music? And, by the way, you are hardware tinkerer? So we actually know you'll like it!

Following this tutorial, you can make a tiny music visualizer, called Piccolo by Adafruit’s team. This is an Arduino project you can make and proudly fit on your desk so that anybody can see how it works. When this gadget notices music around, LED screen begins blinking in respond: "lowest notes toward the left end of the graph, highest notes toward the right".