A carillon (English pronunciation: /ˈkærɨlɒn/, /ˈkærɨljɒn/, or /kəˈrɪljən/; French: [kaʁijɔ̃]) is a musical instrument that is typically housed in a bell tower, or the belfry of a church or other municipal building. The instrument consists of at least 23 cast bronze, cup-shaped bells, which are played serially to play a melody, or sounded together to play a chord. A carillon is played by striking a keyboard - the keys of which are sometimes called batons - with the fists, and by pressing the keys of a pedal keyboard with the feet. The keys mechanically activate levers and wires that connect to metal clappers that strike the inside of the bells, allowing the performer on the bells, or carillonneur, to vary the intensity of the note according to the force applied to the key.
The carillon is the heaviest of all extant musical instruments; the total weight of bells alone can be 100 tons in the largest instruments.
The greatest concentration of carillons is still found in the low countries in Europe: the Netherlands, Belgium, and Northern France, where they were symbols of civic pride and status. Some of the most spectacular are now protected by UNESCO as part of the world heritage site the Belfries of Belgium and France.