So...what I am trying to do is put a block of text above a system that occupies the full width of the page. This is a theatrical work, and the block of text is a stage direction that is paragraph-length.
I do this all the time (see screenshot, attached).
I can create a dynamics context at the top of the score, and attach my markup to a spacer rest at the beginning of that system. But then, Lilypond counts my markup as part of the spacing calculation of the system, which is not the desired effect.
Tweaks are your friend! =)
Change the X-extent (extreme: #empty-interval), etc. and Lilypond won’t even know the text is there.
I have lots of syntactic sugar around this kind of thing — just let me know, and I’ll try to package it up for you to consider and/or use.
Cheers,
Kieren.