I've always wanted a laser harp, and at our first arduino workshop, I realised that a combination of a small lasercard and an LDR could very quickly be turned into a 1-string laserharp. A little bit of design later, and the 10-string monster here, with programmable buttons and LEDs started to come together. It's one meter long by around 58cm high.
All the wood is glued together, with 4 long self tapping wood screws (with guide holes to avoid splitting the wood) in the corners for strength. All the wood was glued together using the wonderful plastic squeezy clamps you see in the background. When I started building these things I was very much out of practise with woodworking, but after a year of trying (and burning lots of funny shaped off-cuts in my fireplace) I am getting much better.