Re: once again with a header, tie into polyphony question

[Rune Zedeler]

Ole Schmidt skrev:

> I want to have both of the first two notes tied -the d and the f-sharp. 
> How do I achieve that?

The problem is, that the Tie_engraver - that generates ties - lives at 
voice level. That means that the Tie_engraver can only "see" notes in 
the same voice - and therefore cannot tie notes from different voices 
together.
The reason why the engraver does not live at Staff level is that this 
would make ties in polyphony impossible. If you for instance have

<<
  e4 ~ e8 e8
//
  c8 c8 ~ c4
>>

Then - if the Tie_engraver were living at Staff level - it would see e 
followed by c followed by e. Therefore the two e's that you try to tie 
together would not be seen as neighbours, and the engraver would be 
confused and produce bad results.

If you really REALLY really need to tie different voice together then 
you can add the tie-engraver to BOTH staff and voice. And manually make 
the ties that you are not interested in invisible.
It goes like this:

%%% BEGIN %%%
\version "2.10.25"

\layout {
  \context {
    \Staff
    \consists Tie_engraver
    \override Tie #'transparent = ##t
  }
  \context {
    \Voice
    \override Tie #'transparent = ##f
  }
}

tiesToVoice = {
  \revert Staff.Tie #'transparent \override Staff.Tie #'transparent = ##t
  \revert Voice.Tie #'transparent \override Voice.Tie #'transparent = ##f
}
tiesToStaff = {
  \revert Staff.Tie #'transparent \override Staff.Tie #'transparent = ##f
  \revert Voice.Tie #'transparent \override Voice.Tie #'transparent = ##t
}

{
  \transpose c c' {
    \tiesToStaff
    < e c >4 ~ < e c >8 < e c > ~
    << { e e e e |
         \tiesToVoice
         e4 ~ e8 e }
    \\ { c8 c c c |
         \tiesToVoice
         c8 c ~ c4 } >>
  }
}
%%% END %%%

I will add this to LSR as soon as I get the \revert \override -thing 
checked. I do not understand why it cannot be replaced with \set.

-Rune