(C Algorithm) "ringing changes"

[Tobias D. Robison]

I am starting a discussion here, I hope, so this note has been
posted to many groups.  Please post followups to fewer groups,
perhaps net.music and net.books!

In article <1557 at sdcrdcf.UUCP> lwall at sdcrdcf.UUCP (Larry Wall) writes,
regarding a permutation algorithm:
>
>Yes, it is interesting.  It looks suspiciously like a change ringing
>algorithm....
>For those of you who haven't heard of change ringing, it is an artform
>practiced by the British in which a set of tuned bells is rung through
>all possible permutations.  For an enjoyable introduction to the topic
>I would recommend the mystery novel The Nine Tailors by Dorothy L.
>Sayers.

The Nine Tailors in NOT an enjoyable introduction to the topic of
bell-ringing!  It is a terriffic teaser, because she never quite
explains to an outsider how change-ringing algorithms work.
I would greatly appreciate explanations, and pointers to books with
better descriptions of change-ringing.

The Nine Tailors is certainly an exciting mystery novel.  It follows
the wonderful principle that the reader should always be one
tantalizing step AHEAD of the master detective in understanding
what's going on.  The underlying plot is so complex that one step
is, of ourse, never enough.  the bells play an integral role in the
mystery; but even for those who guess how, there are plenty of
surprises left all through the book.

One thing about bell-ringing that the book makes clear, is that the
indivual bells are not played all the same.
Some are trickier than others,
and some require more intelligent, or more dependable ringers.
I would be interested to see how this relates to the types of
permutation algorithms that are permitted.

  - Toby Robison (not Robinson!)
  {allegra, decvax!ittvax, fisher, princeton}!eosp1!robison