Georg Gandi, an organist in Ilmenau, constructed a similar instrument with some improvements in 1709 and called it the piano viol. In 1741, two inventors – Le Voir in Paris and Hohlfeld in Berlin – independently constructed versions of a bowed piano, similar to Heyden's design. In 1754, a horsehair covering was added to the wheels of the bowed piano, which was termed the viola da gamba piano.