A bell is a straight struck idiophone percussion tool. A lot of bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides creating a reliable resonator. The strike may be made by an inner clapper or uvula , an exterior hammer, or-- in tiny bells-- by a tiny loose ball enclosed within the body of the bell (jingle bell). Bells are usually cast from bell steel (a kind of bronze) for its resonant properties, yet can also be made from various other hard materials. This depends on the function. Some small bells such as ornamental bells or cowbells can be made from cast or pressed steel, glass or ceramic, but huge bells such as a church, clock and tower bells are usually cast from bell steel. Bells planned to be listened to over a wide area can range from a solitary bell awaited a turret or bell-gable, to a musical ensemble such as an English ring of bells, a carillon or a Russian zvon which are tuned to a common scale and installed in a bel...