When i started making these, i thought of arranging them in two
columns on a single page. To keep the numbers readable, i decided
against this. However, i remain curious. Is it possible to divide a
page into columns? i know that text can be arranged into columns, and
the Internals mention a PaperColumn and its appropriate engravers and
contexts. Having read the sections on page and score layout, i
couldn't find anything that explicitly addressed this problem. i am
working (still?!) in 2.14.2, so the next step just might be an update.
I recently typeset a piece like this - it required a lot of manual
trickery, but it is doable if you use a top-level markup and the
\fill-line command. A recent command was also added by David N. that
helps with this (see https://code.google.com/p/lilypond/issues/detail?id=3860).
It is not automated, so it is a pain, but it comes out looking very nice
- you just have to manually do new markups for new pages.
Wouldn't it be easier to typeset it in the regular way but with page
width set to the desired column width, and then use some PDF or
Postscript manipulation tool to move each pair of pages into one?