Encoding of prolation canons

[rettinghaus]

How should a prolation canon with multiple voices notated as one layer be encoded?
In the very famous example from the Missa l'homme arme super voce musicales one could encode the notes in the three layers with @sameas. But what about the different mensurations?

There's a problem by using staffDef. You could put all three signs as mensur in there, but then you have no connection to the correct layer. And interestingly mensur isn't allowed in layerDef.

My proposal would be to allow mensur and meter as well as keySig and clef to be children of layerDef.

This is somewhat connected to #697.

[craigsapp]

Here is the resolutio:

https://josquin.stanford.edu/work/?id=Jos0603

https://www.youtube.com/watch?v=OrZB-ioh5a4

Here is the Vatican manuscript of the canon (Capp.sist.197.f.0009v):

[craigsapp]

This example is also related to issue #686

The "3" mensuration from the manuscript version is the same as the "cut-c3" in the printed version (presumably by Petrucci?). In this case it is weird to start a piece with a "3" since it usually occurs in the middle of a piece. It does mean sesquialtera (see the resolutio version), where the duration of the breve remains constant, but there are three semibreves instead of two. In all cases I have in JRP it also seems to mean sesquialtera.

In the JRP scores, the "3" mensuration does not start at the beginning of a section (other than this one), and it can be preceded by an O or Cut-O mensuration. In other words, only the "3" is displayed, but the "3" is implied to be in the context of the previous mensuration sign. This mensuration is used interchangeably with colored notes (some parts may be colored while others switch to "3" mensuration), although I would have to examine what happens when the preceding mensuration is O or cut-O.

[kepper]

At ODD Friday, we agreed that the Mensural IG should have an eye on this. @martha-thomae, could you circulate this please? Thanks…

[martha-thomae]

Yes, of course. I will do that this coming week. Thanks!

[ahankinson]

I am going to move this to the discussions section.

[bwbohl]

2021-06-24 ODD Thursday: this discussion will be brought up at the IG mensural meeting.

[bwbohl]

It's already being discussed on the mensural Mailingliste