Mensural notation oddity

[uptoncp]

I'm looking at a Lassus manuscript choirbook (digitised by the Bayerisch Staatsbibliothek). I should say that this is my first venture into mensural notation, and while I'm doing fine with most of it, there's one feature which I can't find described in any online source. At the end of a section, instead of a single note, there sometimes appears,in one part only, a vertical "stack" of two breves, of which the upper is often drawn shorter and is always coloured, while the lower is white. How should I interpret it?

[pateceramics]

This is a subject I know nothing about, but is there any chance you could post a link to a picture, or give the exact title, page, and measure number that you're looking at? Or find an example in a piece in the library here for us to look at? When in doubt, try wikipedia: see anything in this article that looks like what you're looking at? http://en.wikipedia.org/wiki/Mensural_notation

Best,
Maggie Furtak

[anaigeon]

It might be a souvenir of an older (black) notation, in which such stacks did exist ; if that is true, the lower note is played first, and then the upper one, the value of which is somewhat changed by the coloration.
A better guess might be possible by knowing the mensurartion (C or O etc), and yes indeed it would be a good idea to have a picture.
(I don't mean *I* would then give an answer, I'm just an amateur mensuralist as you are)

[Cdalitz]

There is nothing that matches your textual description in this reference in section "Ligatures":

http://music.case.edu/~rwd/Notation/NotationManual.pdf

It seems however that your puzzle could be solved by combining the information in this reference from "Ligatures" with that from "Coloration".

[DaveF]

It sounds like a divisi to me, but can you give us a reference to a particular page? - there are 16 (!) choirbooks containing music by Lassus in the Bavarian State Library, and none of the ones I've looked at contain the feature in question. You can even give the URL of a particular page, e.g. http://dfg-viewer.de/show/?set%5Bimage% ... 0_mets.xml (for example).

DF

[uptoncp]

Here's one: http://daten.digitale-sammlungen.de/~db ... 8/image_73

In the lower part on the page (T of SATB), before the first double bar, end of the word Prophetae. More often the interval is a third, although a fifth here; they're always at the double bar as here. Treating it as a rising ligature would work, anaigeon, but by lengthening everyone else's final note - perfectly reasonable notation-wise, but why colour the second? It doesn't need to add up to anything. Again, if it's a divisi, why the colouration? Surely both must be the same length (which is how I've transcribed so far). There are passages of definite colouration (e.g. pp105-106), and plenty of instances of "minor colouration" for a dotted rhythm, just to establish that Lassus does use that convention.

[anaigeon]

Thanks for the picture !
I've asked the question on Facebook, where I can have contact with some professional musicologists, and there seems to be an agreement about divisi.
In such a case the coloraion of the upper note would be a convention with no metric meaning.
I was told such signs are found in Dufay's Nuper rosarum flores, for example.

[uptoncp]

Thank you, and to all of you who've chipped in. I'm about half way though the set, so hopefully you'll be able to critique the finished product in the not too distant future!