Look, I don't "have a dog in this
fight" (i.e. there's nothing I need Lilypond to do that it doesn't
do, etc.) but I have to protest that
"Lilypond can do this, but nobody, including
lilypond gurus, were able to
do this."
Since someone (i.e Kieren) just did it.
I was going to object to Kieren's statement that it
wasn't particularly difficult (since I think it was), but I have to suppose
that he intended that it wasn't particularly difficult *for him*. As to
why it never been done before, I don't know. I suppose the sets of people
who really wanted it and the people who were capable did not intersect
and the right person didn't get asked. Fortunately, we have this user-list.
I think Kieren's point is that no other music engraving
software has the extensibility that Lilypond has (even if the learning
curve is steep.)
I always know that if I did get to a point where I
need Lilypond to do something that it doesn't appear to do, I can ask here
and someone will likely be able to come up with a way to do it, even if
they need to be motivated by, for example, telling them that lilypond is
incapable. ;-)