Harmen Brethouwer has been working with square panels as a two-dimensional shape and a cone as a three-dimensional shape for over 30 years. He has allowed various artists, designers, and craftsmen to explore these forms, resulting in beautiful outcomes. But suddenly, Harmen had the idea to extract sound from his cones, and after a long process of adjustments and experimentation, the cones were transformed into musical instruments.

His recent experiments have led to a unique development: the transformation of cones into musical instruments. In collaboration with Koninklijke Eijsbouts, Brethouwer has developed the 'Bell Bronzes'. Composer Richard Rijnvos wrote a piece for soprano Keren Motseri and four Bell Bronzes. This work was performed at Museum Kranenburgh in Bergen.