Erik the flutemaker's Ice Age Flute can be found at http://eriktheflutemaker.com/collections/flutes/products/ice-age-flute Inspired by an Ice Age Flute found in a cave in Germany. I passionately sought to make some to see what it would sound like. By blowing up the picture in the article to the stated length I had a great place to start. The last hole on the relic was only partially present so I included that hole and cut the instrument where it was in tune with itself. Later I went wider for better tone. The original was made for a vulture bone. Eventually the flute would have moved into a more mellow sound using wood. Erik the flutemaker.