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## Re: Compound time signature style

 From: Hans Aberg Subject: Re: Compound time signature style Date: Thu, 6 Nov 2014 21:05:36 +0100

```> On 6 Nov 2014, at 20:49, David Kastrup <address@hidden> wrote:
>
>
>>> On 6 Nov 2014, at 14:46, David Kastrup <address@hidden> wrote:
>>>
>>>
>>>>> Am 04.11.2014 um 07:48 schrieb David Kastrup:
>>>>>>
>>>>>>> If the simple-fraction components of a compound time signature
>>>>>>> respected the time signature style, would that qualify as useful or as
>>>>>>> undesirable?  For example,
>>>>>>>
>>>>>>> 2 + 3                2 + 3   4
>>>>>>> ----- + C     vs.    ----- + -
>>>>>>>   4                    4     4
>>>>>>
>>>>>> Undesirable in my book.
>>>>
>>>> It seems everyone agrees for once. :)
>>>>
>>>> One more case: \compoundMeter #’(n d).  The current implementation
>>>> prints this as a fraction (n/d), but I plan to change it to honor the
>>>> style unless somebody objects.
>>>
>>> I lean towards not consulting the style here.  \compoundMeter to me
>>> feels like it should just be numeric.
>>
>> A compound meter can have the same iterated subaccent structure as
>> otherwise indicated in the staff by beaming, only that it occurs
>> metrically. In practise, though, one prefers exceptions. So one idea
>> to implement it would be to have a sequence of patterns recognizing
>> metric rhythms, each assigning a formal compound metric structures,
>> the latter is what is used to typeset the beaming structure.
>>
>> A brief description of this compound metric structure:
>>
>> The smallest structure is "in one”: only an accent at the
>> beginning. Write that as I2, I3, I4, ... (For example, Beethoven’s 5th
>> symphony is normally played "in one", though written in 2.)
>>
>> Then one can combine these using "+" and “(...)": a_1 + a_2 + … + a_k
>> means that there is a stronger accent in the beginning of a_1 than on
>
> Hans, I happen to be an engineer.  Disciplines like Theoretical
> Electrical Engineering work somewhat like telling a mathematician what
> you are currently working with, have him explode into generalized sets
> of equations, work through the notation, reconvert into engineer math
> and figure out how it may be applied to your actual problem.
>
> This feels somewhat similar.  In this particular case, I fail to
> reconnect the dots, however.  I just don't see how your math is supposed
> to relate to figuring out whether to typeset C or 4/4 when writing
> \compoundMeter #'(4 4).
>
> to?

You wanted \compoundMeter to be numeric, so I gave a possible algorithmic
structure, reiterating discussions of the past on LilyPond lists. Once one has
that, the time signature derives from that, the question you are asking about.

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