Re: missing staff lines

[Simon Albrecht]

On 09.10.2017 11:56, Rita Composer wrote:
> I would like to ask your help getting back the added line /or extra 
> staff line (I couldn't find the appropriate name for it either)
>
> So under the common 5 lines in the staff - somehow we lost the 
> automatic cross line for c, or h,
It’s called a ledger line, and the grob is LedgerLineSpanner.

I can’t dig to the bottom of the problem right now, but here’s what I found:
The notes that don’t get ledger lines are wrapped in \melisma{}, which 
wraps them in \neume{}, which replaces their note-head stencil in a 
quite curious fashion that seems to prevent them from being recognised 
by Ledger_line_engraver.  Commenting the overrides to LedgerLineSpanner 
in the gregorianContext definition doesn’t solve the problem.

It seems like you’d need a somewhat simpler solution for your 
typesetting purposes which doesn’t involve replacing the note-head 
stencil with a score markup… can you say why you need that or what you 
are actually aiming for (maybe with an illustration)?

Best, Simon