The meaning of the "3" is basically a short-hand for coloration [in an imperfect mensuration]. In other words the music in the "3" mensuration is played like triplets in modern music notation. The music before the "3" is in Cut-C, and the Cut-C following the "3" cancels the triplets.
So "3" is not a literal mensuration sign so it should not go in staffDef@mensur.sign. (@mensur.sign would technically remain mensur.sign="C" mensur.slash="1", since the mensural context of the "3" is important (for example "3" can occur in O mensuration).
But in this case the "2" is invisible: @proport.num="3" and @proport.numbase="2" for 3 in the time of 2, but with the 2 not being displayed.
I would expect "3" to be encoded in staffDef as @proport.num="3" with no @mensur.sign or @proport.numbase attributes. But @proport.num will only be shown with verovio currently if there is a @mensur.sign in the staffDef as well.
There are less common cases where @numbase="2" is shown:
lpugin
commented
5 years ago
Has it been determined how to encode a "3" mensuration sign? And if so, is it available in verovio? Here is an example case from JRP:
http://josquin.stanford.edu/cgi-bin/jrp?a=notationEditText&f=Jos0301c
The meaning of the "3" is basically a short-hand for coloration [in an imperfect mensuration]. In other words the music in the "3" mensuration is played like triplets in modern music notation. The music before the "3" is in Cut-C, and the Cut-C following the "3" cancels the triplets.
So "3" is not a literal mensuration sign so it should not go in
staffDef@mensur.sign. (@mensur.signwould technically remainmensur.sign="C" mensur.slash="1", since the mensural context of the "3" is important (for example "3" can occur in O mensuration).It seems most like a proportion: https://music-encoding.org/guidelines/v4/content/mensural.html#mensuralProportions
But in this case the "2" is invisible:
@proport.num="3"and@proport.numbase="2"for 3 in the time of 2, but with the 2 not being displayed.I would expect "3" to be encoded in staffDef as
@proport.num="3"with no@mensur.signor@proport.numbaseattributes. But@proport.numwill only be shown with verovio currently if there is a@mensur.signin the staffDef as well.There are less common cases where
@numbase="2"is shown:http://josquin.stanford.edu/cgi-bin/jrp?a=notationEditText&f=Jos2618
A similar case exists with
@proport.numbasebeing shown without@proport.num:http://josquin.stanford.edu/cgi-bin/jrp?a=notationEditText&f=Jos1903
But verovio requires
@proport.numin order to display@proport.numbase.Here is a table of mensurations that are present in JRP (with some of the more esoteric ones omitted):
Six of them: 3, 2, 3/2, O/3, C|/2, C|/3, cannot currently be rendered with verovio.
Note that "3", "3/2", and "O/3" all have the same meaning (at least in Cut-C mensuration), which is a shorthand for triplets (coloration).