Re: \longa and \maxima

[Graham King]

On 6 Jun 2018, at 11:18, Urs Liska wrote:

> And I assume (hope) that the unusual glyph with two stems can be dismissed.

Outside of ligatures, I've never seen a notehead in mensural notation with an 
upstem and a downstem on opposite sides.  Even a plica (which this is not) has 
two upstems or two downstems.  Usually, a longa is a brevis with downstem to 
the right (signifying doubling* the note value), and a maxima is a longa with 
an elongated head (again doubling* the value).  Sometimes the downstem is 
replaced by an upstem (always to the right) without changing the semantics.

An upstem to the left invariably signifies the start of a c.o.p. ligature (the 
last ligature to survive in the era of printing).  This is _not_ a c.o.p. 
ligature (semibrevis-semibrevis).

Perhaps the thing that looks like an upstem here is merely a pointer to the 
explanatory text above the stave?

HTH
-- Graham

*or possibly tripling if modus and/or maximodus are "perfect".