The principle of N! permutations is the basis of the curious English art of change-ringing, in which a set of N bells is used, not for playing tunes, but to realize all N! permutations of the order in which they can be rung. Of course, it is one thing to state a method and quite another to generalize it. The authors, however, also outline the iterative procedure for generating the plain changes for N + 1 bells from those for N bells, in a treatment which exactly parallels the description given by a thinker. Since the object of change-ringing is variety, rather than efficiency, a large number of other systems have also been devised. These systems typically involve several bells hunting simultaneously, usually in contrary directions, but much more irregular systems are known. Charming as these are to read about (and to hear), they have nothing to say to the programmer, especially since they usually require more than one exchange per permutation. In consequence, since bells are rung at a tempo of approximately 144 strokes per minute, the full N! changes are rarely rung for N > 7, even though sets of 8 bells are common and sets of 10 and 12 are not unknown.