Campanology is the art of ringing bells, especially change ringing as it is practiced in England and, to some degree, in the US and Canada.
Called "the poetry of steeples" by Ben Johnson, change ringing is an ancient art. To ring bells precisely on time, the bell is fixed to a circular headstock that rotates the bell on a horizontal axis that is accurately balanced. The bell is held with the mouth up, then a rope wound around the headstock is pulled by the bell ringer, causing the bell to rotate in a full 360-degree arc, coming back to the mouth-up position. As it rotates, the clapper hits the bell at a precise point in the arc, but a time that is different for each size and tone of bell (because their rotational moments of inertia are different). The bell ringer must pull the rope very precisely to make the bell swing exactly through its arc. Pulling too hard, for example, results in the bell hitting its stop as it comes around and bouncing back.
The physics of all this means that it's not really possible to play tunes on a series of large bells like this. They all have to rotate according to their own timing. It does, however, make it possible to ring a round, which is a succession of notes on a cascading scale, think of it as 1-2-3-4-5-6-7-8. This is the sound that accompanies English brides and grooms on thier walk down the isle after their vows.
Very experienced bell ringers can't play songs, but they can, by swinging a bell just tiny bit short of its 360-degree arc, make subtle changes in the timing of the bell ringing that change the order to, say, 2-1-4-3-6-5-8-7. Once the order has been permuted once, it may be permuted again and again, swaping bells one position each time. This is called change ringing and requires great skill on the rope and perfect timing for each bell ringer.
When seven or more bells are used, the number of permutations that can be sequenced is 5040 or more, called a peal, which takes three or more hours of perfect coordination among the bell ringers.
The first peal was rung in England in 1715. The first peal in North America was rung at Christ Church, Philadelphia, in 1850.
References:
http://www.chaddesley-corbett.co.uk/tower_history.htm
http://web.mit.edu/bellringers/www/html/change_instruction.html
http://www.easytorecall.com/bellringing2.htm