Re: Bar lines in hymns

[Dan Eble]

On Jan 16, 2022, at 15:36, Dan Eble <dan@lyric.works> wrote:
> 
> I have a mind to generalize the commands for Gregorian divisiones so that 
> they create breathing signs, bar lines, or scripts over bar lines, according 
> to context properties.  That will serve this case and more, and requires no 
> new terminology.  \section and \finalis would be synonyms, but the other 
> three can be left to the user to name as they please, for example,
> 
>  phraseDiv = \divisioMinima

This is how I see things taking shape.  Most of this exists in prototype but 
some is still speculative.

\caesura is promoted to a global command calling for a short break outside of 
the notational timeline.  It accepts arbitrary articulations, e.g.,

    \caesura \fermata

Caesura_engraver operates in Staff context (but is removed from ancient 
contexts) and engraves \caesura as a BreathingSign, optionally with scripts, or 
as script(s) attached to a BarLine, depending on a convenient set of context 
options and callbacks.

Bar_engraver supports options for inserting distinctive bar lines at \caesura.

In gregorian.ly,

    virgula = { \once \override ... \caesura }
    divisioMinima = { \once \override ... \caesura }
    divisioMaior = { \caesura \shortfermata }
    divisioMaxima = { \caesura \fermata }
    finalis = \section

Divisio_engraver operates in ancient Voice contexts and reacts to the above as 
required.  (It ought to be Staff contexts, but I worry about breaking existing 
scores.)
— 
Dan