I once met a percussionist/composer who made his living for about a year (okay, I suspect he supplemented it by dumpster diving) doing film music with an instrument he called the Mazdaphone. It was made from a Mazda hubcap fished out of a river, strung with springs from a Bullworker that he'd found in somebody's trash. The variety of sounds and rhythms he could get out of it by various scraping and banging techniques, together with a bit of clever sound studio work, was enough to emulate a whole percussion band.