William Close, inventor of the Earth Harp: Love playing with the audience inside the instrument

William Close is the inventor of the Earth Harp, the world's longest string instrument, which has strings dozens of meters long, and it uses architecture or landscapes to stretch the strings, creating a unique sound. This also means that the audience in a concert venue is actually inside the instrument, which, as he's told the BBC, he especially likes. It's called Earth Harp because the first he installed, Williams Close, it was in a canyon, but it actually sounds more like a cello.