[MEI-L] [Tuplets again &] Example: non-integer divisions of the whole note

[Byrd, Donald A.]

Sorry, but I'm not convinced. NB: Perry, maybe you didn't see my 
response of yesterday yet; if so, forgive me for "beating a dead horse".

The Byrd & Isaacson paper defines duration unit like this: "in a 
tuplet, the duration to which the tuplet’s numerator or denominator 
refers. In the vast majority of cases, the numerator and denominator 
duration units are the same. These values are derived from our 
colloquial descriptions of tuplets, for example, 'Three eighth notes 
(the numerator and its duration unit) in the time of two eighth notes 
(the denominator and its duration unit).' In Craig's case, like almost 
all, the duration units are the same. But what about the Elliott Carter 
example I gave the other day (Example 1f of Byrd & Isaacson; attached)? 
This is a group of 7 dotted 16ths, marked "7 = dotted half". OK, the 
encoder could figure out this is 7 in the time of 8, _if_ they don't 
get confused. Gardner Read's book Modern Rhythmic Notation gives 
several other examples, e.g., "7 16ths for 3 eighths" in Stravinsky's 
Variations in Memoriam Aldous Huxley, and I'll bet there are even worse 
things in Carter. I'm pretty sure there are cases where the _only_ way 
to describe a tuplet is with different duration unit for the numerator 
and the denominator; regardless, my figure 1f and the Stravinsky are 
cases where that's the _best_ way to describe a tuplet, (1) because 
that's the way the composer (or editor) wrote it and (2) because 
forcing people to encode it in terms of a single unit is likely to 
cause mistakes!

To summarize, describing some tuplets requires more than just giving a 
rational number -- in Craig's case, 7:6. And in some cases it's much 
better to be able to express different duration units for nummerator 
and denominator. I don't know how MEI should express things, though, 
and I don't have time to think about it now.

--Don


On Fri, 14 Aug 2009 08:25:55 -0400, "Roland, Perry (pdr4h)" 
<pdr4h at eservices.virginia.edu> wrote:

> Craig,
>
> Thinking more about your question and my answer, I'd like to amend
> what I said before.
>
> Your specific question -- "Where do I put the '6'?" -- made me
> realize that @numbase should not be a duration but rather a positive
> integer.  With that change, it is possible to put '7' in @ num and
> '6' in @numbase.  @dur and @dots then should represent the duration
> of the tuplet, in this case '2' and '1', respectively.
>
> There's nothing in the DTD that keeps you from using these values
> now.  It's just the documentation that's wrong.  In the RNG the
> datatyping is enforced.  Both will need to be fixed.  I'll add these
> changes to my list and mark them priority one.
>
> Sorry for the confusion,
>
> --
> p.
>
> __________________________
> Perry Roland
> Digital Curation Services
> University of Virginia Library
> P. O. Box 400155
> Charlottesville, VA 22904- 4155
> 434-982-2702 (w)
> pdr4h at virginia.edu
> ________________________________________
> From: mei-l-bounces at lists.uni-paderborn.de
> [mei-l-bounces at lists.uni-paderborn.de] On Behalf Of Craig Sapp
> [craigsapp at gmail.com]
> Sent: Wednesday, August 12, 2009 7:40 PM
> To: Music Encoding Initiative
> Subject: Re: [MEI-L] Example: non-integer divisions of the whole note
>
> Hi Perry,
>
> From a computational viewpoint, I cannot see how to extract the rhythmic
> information from the example encoding:
>
> <score>
> <scoredef key.sig="3s" meter.count="3" meter.unit="4">
>   <staffdef n="1"/>
> </scoredef>
> <section>
>   <measure>
>     <staff n="1">
>       <layer n="1">
>         <tuplet num.place="above" num.format="count" bracket.visible="false">
>           <note pname="a" oct="4" dur="8"/>
>           <note pname="c" oct="5"/>
>           <note pname="e"/>
>           <note pname="g"/>
>           <note pname="e"/>
>           <note pname="g"/>
>           <note pname="a"/>
>         </tuplet>
>       </layer>
>       <layer n="2">
>         <tuplet num.place="below" num.format="count" bracket.visible="false">
>           <note pname="e" oct="4" dur="16"/>
>           <note pname="d"/>
>           <note pname="c" dur="8"/>
>           <note pname="e"/>
>           <note pname="a"/>
>           <note pname="g"/>
>         </tuplet>
>       </layer>
>     </staff>
>   </measure>
> </section>
> </score>
>
> Either the logical duration of the <tuplet> or the <note> needs to be
> explicit,
> or the tuplet factor needs to be explicit.  For example: "7 in the
> time of 6" for
> the first layer. The "7" can be extracted (painfully) from the data, but the
> "6" cannot.  Relying on the logical duration of the <measure> will work in
> this particular case, but not in the general case. Suppose that you have:
>
> <measure in 3/4 meter>
>    <tuplet/>
>    <tuplet/>
> </measure>
>
> Who is to say that the first tuplet takes two beats and the second tuplet
> takes one beat, or vice-versa?
>
> An unrelated question: you didn't specify oct/dur values for all
> notes.  Is this just
> due to being parsimonious for illustration purposes, or is this an
> allowed property
> of (note) attributes in MEI to inherit unset attribute values from previous
> elements (notes)?
>
> -=+Craig
>
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--
Donald Byrd
Senior Scientist
Adjunct Associate Professor of Informatics & Music
Indiana University, Bloomington
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