Comment #10 on issue 3160 by [email protected]: chord names pushed into the staff
http://code.google.com/p/lilypond/issues/detail?id=3160
the idea for vertical axis groups with empty skylines that do not have remove-empty set is to omit them but ...
Well, I would think it simpler to leave lines in place, if remove-empty is false. That is, leave the VerticalAxisGroup data structure in place, and let the spacing engine simply notice that there are no collisions with the empty line, so insert a spacing spring (rod) as usual with the basic(minimum)-distance.
But you're the programmer so you can implement as you like.
