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## Re: TimeSignature with note in denominator

 From: David Kastrup Subject: Re: TimeSignature with note in denominator Date: Sun, 14 Nov 2021 20:11:03 +0100 User-agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux)

```Kieren MacMillan <kieren@kierenmacmillan.info> writes:

> [David K:]
>> 8/20 does not specify more than the basic
>> subdivision for expressing beats (not necessarily identical with the
>> number of beats as signatures like 9/8 show)
>
> Ah, I think I now see where your confusion lies.

It's great that you show so much patience with rank beginners in
LilyPond.

> The time signatures 8/20 and 9/8 *do* function identically:
> — the bottom number identifies the duration, *expressed as a fraction
> of a whole number*, that should be considered the functional division
> of the measure;

And here is where your plan falls down because LilyPond's definition of
a duration does not agree with the words you are comfortable throwing
around because of your education.  What you are thinking of is a Moment,
the unit in which the _length_ of a duration is expressed.  There is no
1:1 mapping between moments and durations: various different durations
may correspond to a single moment when involving scale factors, and lots
of moments don't have corresponding durations when you forego scale
factors.

> — the top number identifies how many functional divisions are required
> to fill a complete measure.
>
> *By convention*, traditional classical music groups the 9
> one-eighth-of-a-whole-note events into three groups of three each,
> leading people to say that the duration of a “beat” is equal (in that
> case) to three eighth notes.
>
> The time signature “9/8” does *not* (as you imply) actually convey
> *any* information about the number of “beats” — the *convention* does
> that.

I am certain you will be able to provide a definite quote where I
"imply" any such thing.

> I suppose Carl and my surprise (revelation?) is that Lilypond has
> *never* handled time signatures correctly (where “correct” means
> “according to the accepted definition of 'time signature'”).

Nor has his ever handled durations correctly according to your
definition of "duration".  Which means you should get a grip on what
LilyPond calls a duration before proposing to use it.

--
David Kastrup

```