[Choral] Voices/staves - moving from tenor/bass to T1/T2/B1/B2 and back

[Peter Wright]

Hi all,

I have a sneaky suspicion I'm approaching this problem in completely
the wrong way, and I'd appreciate any suggestions on how to do it
in a way that works.

I'm trying to typeset a choral piece which starts out with just a
tenor line and a bass line. No problem. Then the tenor line and bass
line each split into T1/T2 and B1/B2 before reverting to T/B.

I'd *like* to render this as starting with two staves and then moving to
four, then back to two (note: trying to keep the two tenor voices in the
same staff is technically possible but wouldn't work very well and
is not what I want - same with the two bass voices).

I started with an attempt to follow the snippet "Adding an extra
staff" in this section of the Snippets List:

http://lilypond.org/doc/v2.11/input/lsr/lilypond-snippets/Staff-notation

My example attempt (just two bars) is here:

http://flooble.net/~pete/staff-split-example.ly

...and the result here:

http://flooble.net/~pete/staff-split-example.pdf

Argh :). As you can see, there are two major problems with this result.

First - the "new" staves were both added at the bottom. I was hoping the
new tenor staff would be added below the existing tenor staff and the
new bass staff below the existing bass staff. Is there a way to make
that happen?

Second - the ambitus engraver is not acknowledging the extra pitch
range caused by the E semibreves in the tenorTwo and bassTwo lines.
I can see that makes sense in a way - probably the ambitus only
applies to the music of the first bar - but I would have liked it to
apply to the entire range of the tenor voice (both tenorOne and
tenorTwo) and similarly with the basses. Is there a way to accomplish
this?


As suggested in my first paragraph above, I'm starting to think I've
approached this in the wrong way - that perhaps there might be a more
elegant solution for this kind of problem.

Or perhaps I'm on the right track and I've just got a few technical
details wrong. :-)

Any suggestions much appreciated, thanks.


(I'm using Lilypond 2.10.33, just in case it matters.)

Pete.
-- 
A debugged program is one for which you have not yet found the conditions
that make it fail.  -- Jerry Ogdin