Making music through logic
A set of bells (called a “ring” of bells) commonly comprises 5, 6, 8, 10 or 12 bells. Each is tuned to a specific note and each is rung by a single person pulling a rope below the bell. If you think of the bells being numbered, the simplest sequence to ring 10 bells would be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. By moving bells up and down the ringing order by calling out changes, a new sequence or method is created. Pre-set sequences are given names and committed to memory, so that when a method is called, ringers know when his or her bell must sound. A method that consists of sufficient numerical changes and which meets set criteria can be called a peal.
Image: A change ringing method called “Cambridge Surprise Minor” on six bells. The red and blue lines show the number of the first and second bells through the sequence.
Depending on the number of bells employed, the number of variations in the striking sequences (and by extension, the number of sound combinations we hear standing on the ground below) can vary greatly. For instance, a full peal on 10 bells, consisting of 5,040 changes, would take nearly 3.5 hours to complete.
As one might deduce, a full peal is only attempted on special occasions. In fact, it would take approximately 123 days, ringing continuously day and night, to ring all the possible mathematical permutations on 10 bells. We can’t imagine the neighbors would be too pleased.
Section image: Ropes hung for change ringing in the tower of Crowland Abbey, Lincolnshire, UK.