Two weeks ago Dan asked the following:
>> Can you force them to face each other?
>
> I think so, yes, with some TeX trickery.
I've now had a closer look. Currently, LilyPond's PDF documentation
is created in single-side mode, i.e., the page numbers are always in
the upper right corner. It is possible to get a two-sided layout by
inserting `@setchapternewpage odd`; this also makes chapters always
start on an odd page. This first page of the visual index chapter
could be used for some explanations, and the next two pages would be
then facing each other, as desired.
However, I think it would be still necessary to create the visual
index outside of the `lilypond-book` framework; the necessary tight
vertical typesetting is rather diametral to splitting the snippet into
single staves that are then glued together as boxes with some vertical
space inbetween, causing far too large vertical distances.
Werner
