mixed meters

[axgeertinger]

Sorry to re-submit this issue, but I cannot see how to get Verovio to display mixed meters without using a hack. I would expect a meter like this:

to be encoded like this:

<measure>
  <staff n="1">
    <layer n="1">
      <meterSigGrp func="mixed">
        <meterSig sym="cut"/>
        <meterSig count="3" unit="1" form="num"/>
      </meterSigGrp>
    </layer>
  </staff>
</measure>

As far as I know, the combination of a symbol and a number is a fairly common feature in 17th and 18th century music.

[craigsapp]

Cut-C 3 also occurs occasionally in early Renaissance music (roughly 1% of works contain that mensuration).

Example scores (in modern notation using original note durations and mensurations):

http://josquin.stanford.edu/cgi-bin/jrp?a=notationEditText&f=Jos2830

As a mensuration at the start of a section, page 8 of this work:

http://josquin.stanford.edu/cgi-bin/jrp?a=notationEditText&f=Jos2313

As a mensuration change, page 5 measure 170 of this work:

http://josquin.stanford.edu/cgi-bin/jrp?a=notationEditText&f=Jos1612

[lpugin]

Looking at the example you previously sent I would expect this

<mensur slash="1" tempus="2" prolatio="2" num="3" />

If we are talking about a modern transcription, I do wonder if this is really two elements. It seems to me that this would be as appropriate

<meterSig count="3" unit="1" form="num" sym="cut"/>

Now the problem is that a lot of data have both symbol and numbers (typically 4/4 and C), and I think verovio currently shows only the symbol when both are provided. This is debatable. However, if we decide that verovio should not change its current behavior, we could make it show both the symbol and the numbers but only with @form="num|denomsym|norm". Does this sound acceptable? (I can see the need for meterSigGrp with mixed meters, which is not the case here.)

[axgeertinger]

The guidelines say that

@sym (optional) Indicates the use of a meter symbol instead of a numeric meter signature

so Verovio's current behaviour (displaying the symbol only, if both are provided) seems to be correct according to the guidelines: apparently, neither <meterSig> nor <scoreDef> is intended to display both the number(s) and the symbol. There is no @form value for displaying both. I agree that the example is not really a mixed meter, but actually none of the @func options (alternating | interchanging | mixed) seem to be quite accurate in this case. Perhaps I should make that a schema issue, but that's a different story; the @func values would probably not affect Verovio's rendering.

[lpugin]

None of the @func options (alternating | interchanging | mixed) seem to be quite accurate in this case. Perhaps I should make that a schema issue

Alternatively you can suggest a change to meterSig@form in order to trigger the display of both the symbol and the numbers. This looks historically more correct than extending the use of <meterSigGrp>

[axgeertinger]

Yes, will do.

[craigsapp]

and I think verovio currently shows only the symbol when both are provided.

This would be useful for JRP encodings. I encode both the mensuration and the modern time signatures. If someone wanted to only show in modern time signatures, they could remove the metric symbol information.

<mensur slash="1" tempus="2" prolatio="2" num="3" />

The meaning of Cut-C 3 is equivalent to "3" when the prevailing mensuration is Cut-C. In other words, the tempus goes from 2 to 3 (keeping the same time duration for the breve), so the above encoding looks funny in the logical sense, although graphically it makes sense.

Cut-C 3 is a fast triplet tempo, functioning similar to 6/8 in modern notation. Circle mensuration is a slow triplet tempo (similar to 3/4 in modern notation) and Cut-Circle is a medium tempo (roughly 3/2 in modern notation). Using this mensuration in 18th-century notation probably keeps the same meaning of a fast 6/8 sort of meter --and putting the fermata over the mensuration probably is a proleptic way of saying the music should be sung slower than regular Cut-C 3 music (substituting what should probably be notated in C-dot mensuration). C-dot is not very common in Josquin's music, and is almost only found in tenor quotations of older music.

[lpugin]

Looking at meterSig@form, it reads for 'invis' "Meter signature not rendered." I would assume this also to apply to @sym and not only to the numbers. So there is definitely something to clarify and to refine in the MEI guidelines here.

[axgeertinger]

@lpugin: Yes, that's how I understand @form="invis" too. @craigsapp: Thanks for the explanation! Mensural notation is a little beyond my usual field of work, but luckily I'm only responsible for the technical solution in this case. I'll pass your comments on.