A crystallophone is a musical instrument that produces sound from glass.One of the best known crystallophones is the glass harmonica, a set of rotating glass bowls which produce eerie, clear tones when rubbed with a wet finger.The glasschord (or glasscord) resembles the celesta but uses keyboard-driven hammers to strike glass bars instead of metal bars.The glass marimba is similar to the marimba, but has bars of glass instead of wood.