Change Ringing

Change ringing is the art of ringing a set of tuned bells in a controlled manner to produce variations in their sounding order.

Change ringing originated following the invention of English full-circle tower bell ringing in the early 17th century, when it was found that ringing a bell through a large arc of swing gave more control over the time between successive strikes of the clapper. This culminated in ringing bells through a full circle which allowed ringers to easily produce different striking sequences; either called out by one of the ringers, known as "Call changes", or continuously changing sequences following mathematical rules, known as "Method ringing".

The considerable weights of bells employed in full-circle ringing means that they cannot be easily halted, and the change of speed between successive strikes is limited. Therefore in change ringing each bell strikes once in each sequence, and only moves one place in the striking order of successive sequences. These constraints give change ringing its basic rules for generating sequences, which are known as "changes". Control is exerted by the ringer when each bell is mouth upwards and moving slowly near the balance point, and the rope management involved means that each bell nearly always requires its own ringer. The weight of a tower bell means it can only strike once about every two seconds—the time for a full rotation in one direction.

Although change ringing is practised worldwide, it is by far the most prevalent on church bells in English churches, where it was first developed. Such a church's ring of bells requires each bell to swing freely for slightly more than one revolution in alternate directions. Change ringing is also performed on handbells, and on carillons (where the bells are fixed and struck with hammers) though both of these instruments are more commonly used to play conventional melodies and employ harmonies.

Today, some towers have as many as sixteen bells that can be rung together, though six or eight bells are more common. The highest pitch bell is known as the treble, and the lowest is the tenor. For convenience, the bells are referred to by number, with the treble being number 1 and the other bells numbered by their pitch—2,3,4, etc.—sequentially down the scale. (This system often seems counter-intuitive to musicians, who are used to a numbering that ascends with pitch.) The bells are usually tuned to a diatonic major scale, with the tenor bell being the tonic (or key) note of the scale. Some towers contain additional bells so that different subsets of the full number can be rung, still to a diatonic scale. For instance, many 12-bell towers have a flat sixth, which if rung instead of the normal number 6 bell allows 2 to 9 to be rung as light diatonic octave; other variations are also possible.

...
Wikipedia