I'd like to skip the arduino step and go straight to the closest thing I can output commands to from a PC. Do you have an online store? Once the prototyping and testing is finished, I'd like to order these in small batches periodically. I'd want a populated board with leads for the LEDs. An 88-key grand piano's key area is 4ft wide so the longest LED lead would need to be a little over 4ft long. It would be better to have one, long, 4ftx0.5", flat, PCB with the little micro LED's on it and all of the other components. A flexible strip would be better still.