The glass harp consists of a set of wine glasses of various sizes, filled with different amounts of water to achieve specific pitches. The musician plays by rubbing their wet fingertips around the rims of the glasses, creating a 'singing' sound through friction. This phenomenon is known as 'stick-slip' vibration. Smaller glasses or those with more water produce higher pitches. While Benjamin Franklin’s Glass Armonica automated the process with a rotating spindle, the glass harp remains a manual and highly delicate art form. It requires extreme cleanliness, as even a small amount of oil from the skin can prevent the fingers from 'gripping' the glass to create the vibration.