mensuration signs as metrical symbols

[craigsapp]

For JRP, I need mensuration signs to be displayed as metrical symbols with otherwise modern common music notation.

I see in libmei that there are two metric signs and two mensurations:

https://github.com/rism-ch/verovio/blob/master/libmei/atttypes.h#L413-L429

/**
 * MEI data.MENSURATIONSIGN
 */
enum data_MENSURATIONSIGN {
    MENSURATIONSIGN_NONE = 0,
    MENSURATIONSIGN_C,
    MENSURATIONSIGN_O,
};

/**
 * MEI data.METERSIGN
 */
enum data_METERSIGN {
    METERSIGN_NONE = 0,
    METERSIGN_common,
    METERSIGN_cut,
};

Here are the main mensuration glyphs in SMUFL that I would need (humdrum name listed before, and colloquial name after the entity encodings for the symbol in SMUFL):

mensuration "O." (the capital letter "O" and a period): ܅ or  (called "Circle dot"):

mensuration "O" at ܆ or  ("Circle")

mensuration "O|" at ܇ or  ("Cut Circle")

mensuration "O|." at ܈ or  ("Cut Circle Dot")

mensuration "C." at ܉ or  ("C Dot")

mensuration "C" at ܊ or  ("C")

mensuration "Cr" at ܋ or &#E916; ("Reverse C")

mensuration "C|." at ܌ or &#E917; ("Cut C Dot")

mensuration "C|" at ܍ or &#E918; ("Cut C")

mensuration "C|r" at ܎ or &#E919; ("Reverse Cut C")

Some of these are needed in a compound form with a number beside and/or below (the mensural numbers are also in SMUFL, but some digits are missing). Here are the counts of the number of each mensuration sign in JRP with multiple code points given for compound glyph mensurations, sorted from most common to least common in the database:

6775         C|           Jos2721      
2198         O            Jos2405      
1194         C            Mar2020      
921          3            Mar3020      
702          C2           Rue1004b     
333          O|           Rue1005e     
193          C|3          Rue1007d     
155          O/3          Jap3009      &#e911; over 
139          O2           Jos0401d     
101          C3           Gas2017a     
64           C.           Bus1001a     
50           O.           Bus1001b     
29           3/2          Jos1903      &#e928; over &#e927;
26           O3           Bru2012      
21           C|2          Ort2004      
17           2            Jos0402e     
13           O3/2         Tin1001c      over 
10           O|3/2        Jos0903b      over 
10           O|3          Jos0406b     
8            C.3/2        Mar2079      㤨 over 
7            Cr           Rue1001b     
6            C|/3         Jos0406d     &#e918; over 
5            C.|          Ock1013e     
4            C|/2         Jos0902d      over 
4            C2/3         Tin1001b     &#e927; over 
4            2/1          Tin1001a      over 
3            C|r          Bus1001c     
3            C|.          Ock1008b     
2            4/3          Tin2001       over 
1            C.3/8        Tin1001e      over 8 (no "8" mensural glyph)
1            6/4          Tin3006      6 over 
1            2/3          Tin2001      &#e927;      over 
1            14/18        Tin3006       over 8

The third column contains a sample work in the JRP database that contains this mensuration. Typically the mensuration is at the start of the work, but for rare mensurations, you will have to search inside the work for the matching mensuration.

Here is a sample URL for "O2" in the list (Jos0401d): http://josquin.stanford.edu/cgi-bin/jrp?a=notation&f=Jos0401d

Graphic example from first system:

[lpugin]

We can add all these in the Leipzig font. (We used to draw them directly, but since they are in SMuFL we can add them.) I also noticed the fact that there is no "8" (and other figures). Are they really original figures? I suspect they are transcription proportions. In that case you will probably need to use modern time signature figures. This will probably have to be an option in Verovio since I do not see a proper way to make the difference in MEI. @donbyrd : what do you think?

[craigsapp]

I suspect they are transcription proportions. In that case you will probably need to use modern time signature figures.

They are original to the music. All of the problemmatic ones are related to Tinctoris, who had his own ideas on how mensurations should be notated. 6/4 can be faked somewhat as a 6/4 time signature, but 2/3 and 14/18 may be more difficult (depending on if non-power of two numbers are allowed in the bottom spot of the time signature). But then how would timestamps work with respect to a dummy time signature?

Definitely not a priority, as I have not dealt with it yet in MuseData:

[craigsapp]

By the way, here are the JRP scores in VHV:

http://verovio.humdrum.org/?file=jrp/Jos

You can replace "Jos" with any other composer abbreviation:

Ano Agr Bru Bus Com Das Duf Fva Gas Isa Jap Jos Mar Mou Obr Ock Ort Pip Reg Rue Tin

Or special genre codes Zso (songs), Zmo (motets), Zma (masses), Joa (secure Josquin attributions), and Job (not secure Josquin attributions).

The scores are in full modern notation, as I don't yet convert special formatting for modern notation closer to the original mensural notation (such as mensuration signs in particular).

[donbyrd]

Craig says the problem cases are original to the music, and he points out that 2/3 and 14/18 (e.g.) will be difficult to fake with pseudo time signatures, even if non-power-of-2 denominators are allowed. That suggests that MEI really should be extended to handle these Tinctoris-style proportions, no? If I remember correctly (I can't test it now), Verovio can already draw such proportions, regardless of whether they're valid MEI! But this surely isn't high priority, especially since Craig says it's not a priority for him. That's all I can think of offhand, and I'm about to start a 3.5 day ascent of Mt. Rainier, where to my knowledge Internet access isn't available :-) , so I'll probably be out of touch until next Tuesday.

[lpugin]

I am not sure I see the problem with MEI (and Verovio). They are proportions (and not time signatures) and are handled as such in Verovio. My question was only about the glyph to be used for them, and in particular the fact that all digits shown here are not available in the SMuFL mensural group.