Traditional English art of ringing tower or hand bells in a succession of different orders.
Groups of swinging bells in English church towers date from the 10th century. Control of bell ringing was much enhanced with the invention of the bell wheel in the 14th century; further improvements in bearings and fittings allowed the bells to swing at the same speed and led to recognizably modern change ringing by the 17th century. A "ring" (set) of 6 bells can be tolled in 720 different "changes" (orders); 8 bells allow 40,320 different changes, and 10 bells allow more than 3,000,000. In practice, only a selection of the possible changes is rung, derived by a "method" (a shuffling algorithm), usually involving switching pairs of bells in a certain order (e.g., 123456 becomes 214365, which can then become 241635, etc.). "Rounds"
all the bells in order from highest to lowest
is rung before and after a method is completed.