> Hello,
>
> I'd like to write this song with Lilypond:
>
http://www.taize.fr/spip.php?page=chant&song=203&lang=en
> (in fact I'm writing with portuguese lyrics)
>
> Just so you don't need to click the site, here's the problem. Many of these
> songs have identical rhythm, except for some parts. When the rhythm is the
> same, I want to have same stem direction (may be neutral), because all
> originals are like this and seems to be easier to read than with four
> separated voices with opposite stems. When the rhythm is not the same, I
> want to fallback to 1-2-3-4 voices being S=stemUp, A=down, T=up, B=down.
% \partcombine usually helps