A bell is a percussion instrument consisting of a metal casing with some way of striking the casing to produce a tone. Some bells, particularly large ones, have a clapper suspended inside. When the bell is rocked back and forth, the clapper strikes the inside of the bell, producing a tone. Other bells are struck with mallets to produce a tone, and some very small bells take the form of small spheres with a small ball inside. These bells are shaken to produce a tone.
Bells play an important role in culture, historically and in the present day. The Liberty Bell is famous symbol of American freedom. Bells are associated with churches, especially churches of classical design, which often incorporate bell towers. Chains of small bells, called jingle bells, are associated with cultural celebrations of Christmas.