[r-t] Complexity of extents

Richard Smith richard at ex-parrot.com
Mon Jun 24 22:48:50 UTC 2013


Andrew Johnson wrote:

>> From: Richard Smith <richard at ex-parrot.com>
>> But when I try to get an extent with rotational symmetry, it
>> feels like I'm fighting against the symmetry rather than
>> utilising it.
>>
> It's not an extent, but for rotational symmetry were
> you thinking of compositions such as Ander's 5024 Bristol S.
> Major?

Not really.  I think the difference between an extent an 
eighth-extent (a peal of major) is significant.  I was 
thinking more of extents on four, five or six.  I can't say 
I've ever tried to produce a rotationally symmetric peal of 
major.

Naïvely you wouldn't necessarily expect a rotationally 
symmetric extent to be any harder to produce than a 
palindromic one.  Both symmetries constrain half of the 
rows.  But, at least in my experience, a rotationally 
symmetric extent (that's not also palindromic) feels a much 
tougher proposition than a palindromic one.

RAS


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