Homebrew Musical Instruments?

Josh Booth asks: "Has anyone ever built a musical instrument? I recently built two, a SSPACaRTD (Single String Plucked Air Compression and Rarifaction Tunable Device), and a full size string bass for the NJ State Science Olympiad. I played the bass and, since we did the required duet, my friend played an End Struck Plosive Aerophone, or a set rather, like what the Blue Man Group plays. We placed fifth out of 20+ schools. My bass is similar to those that Dennis Havlena made and used weedwhacker line for strings. I was wondering whether anyone else tried to build an instrument. How did you do it, what did it sound like, and how weird was it?"