Doubles (bells)

Change ringing is the art of ringing a set of tuned bells in a controlled manner to produce variations in their striking sequences. This may be by method ringing in which the ringers commit to memory the rules for generating each change, or by call changes, where the ringers are instructed how to generate each new change by calls from a conductor. This creates a form of bell music which is continually changing, but which cannot be discerned as a conventional melody.

Change ringing originated following the invention of English full-circle tower bell ringing in the early 17th century, when bell ringers found that swinging a bell through a large arc gave more control over the time between successive strikes of the clapper. This culminated in the custom of ringing bells through a full circle, which enabled ringers to accurately ring continually-changing sequences, known as "changes".

Speed control of a tower bell is exerted by the ringer only when each bell is mouth upwards and moving slowly near the balance point; this constraint and the intricate rope manipulation involved normally requires that each bell has its own ringer. The considerable weights of full-circle tower bells also means they cannot be easily stopped or started, and the change of speed between successive strikes is limited. This in turn places basic limitations on the rules for generating easily-rung changes; each bell must strike once in each sequence, but its order of striking in successive changes can only change by one place.

Change ringing is practised worldwide, but it is by far most common on church bells in English churches, where it first developed. Change ringing is also performed on handbells, where conventionally each ringer holds two bells, and chimed on carillons and chimes of bells; though these are more commonly used to play conventional melodies.

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.

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Wikipedia