Scraper Flute is my name for a tube with ridges formed by grooves cut into the surface. The air column is set to vibrating by scraping over the surface of the tube with a metal rod. The resulting agitation of the tube wall excites the air within. The length of the tube determines the pitch. The tubes can be made of plastic or bamboo — different materials make different tone qualities. The version shown here is a flexibly mounted set of tubes forming a chromatic scale. I’ve also made scraper flutes with flute-like tone holes so that a scale can be produced with a single tube.
In the audio clip, the scraper flutes are joined by several bird calls and miscellaneous percussion.