Ten stone plates, despite being the same size, vary in pitch from high to low. The stone is what makes the difference. 

The Lithophone lets the visitors exerience how the difference in texture and consistency of stones influences the tones they produce. The hanging plates are all the same size but vary in terms of their materials or sometimes simply in terms of their thickness. 

The Lithophones of the MobileMusicMuseum can be found here: 

Sounds of the stones in the area of the stones: a Lithophone steers the visitors from the collection of the Music Museum towards a piece of the history of the Earth at the chalk-pit Bochumer Bruch, in the "Time-Tunnel" Wülfrath (Zeittunnel Wülfrath) Museum. more...

Sounds of the stones along the Sound Trail in the Nature Park Our. more...