# [r-t] 8 spliced atw 7com

Mark Davies mark at snowtiger.net
Thu Mar 29 12:59:24 UTC 2012

```Rob writes,

> I've seen it sent up as 113 or 112 com and
> this gives a handy indication of who's chickened out and called the split tenors
> section at the start rather than the end.

Surely there are other starting points which, when counted via the
"conductor's method", would muddy your conclusions! I guess it's
unlikely anything else would be rung in practice (although I might just
organise that peal... :-)

Anyway, to me, this adds to the argument. It's the same composition no
matter whether you have the split-tenors section first or last. (No one
would consider they had called anything other than Holt's original just
because they had rung the S--S section first not last!) Hence, it ought
to have the same COM.

> Not all properties of a composition are invariant under rotation. Yes,
> truth and length are. But lots of interesting ones aren't: musical
> rows a composition contains, ease of calling, whether or not it's
> tenors together, whether it's particularly easy for handbells.

I think that all stable properties of a composition are either (a)
invariant under rotation, or (b) variant, but dependent only on the
transposition from rounds to the starting row you have chosen. For
instance, if you start a round-block from a course end marked as
14235678, the music, ease of calling, tenors-togetherness, and
suitability for handbells, are all determined by the transposition
12345678->14235678. In this example, we can immediately see that 5678
music will be unaffected; the tenors will be together if they were in
the original, and not if not; and that the 5-6 handbell pair will be as
before (and the 3-4 pair too, if this is a course end).

This means that composition properties partition into two nice sets, one
set independent of rotation, the other only dependent on the starting
transposition of the rotation. "Conductor's COM" fails to appear in
either set, therefore it is not a stable property of a composition. QED!

MBD

```