Is there a case for introducing scoped variables into Lilypond?
As I understand it (please correct me if I'm wrong), variables have to be declared at the top of the document, before any music _expression_. I'm trying to work on a document with many different scores, each if which is in its own file. According to what I gather is best practice I use variables to hold the basic music text: one variable for each staff. When engraving each individual score, I need to put its variable declarations at the head of its file. But when I want to gather them all together into a book or bookpart, this doesn't work, so each score has to be edited to remove the definitions.
One way round this would be to allow Lilypond variables to be defined within bookparts and/or scores, and to give them a scope confined to that section. See the following MNWE.
I realise that this would probably be a major change, and so I hesitate to suggest it formally unless there is a consensus of opinion in its favour. It would however make "bottom-up" document production a lot easier, as local information would be encapsulated. This, after all, has been best practice in language design for some time now.