New lyrics trick available in 2.9.6

[Erik Sandberg]

Hi,

As a side-effect of my recent cleanups in the 2.9 branch, there's a new trick 
for advanced uses of \lyricsto. If you want to do something very nonstandard 
in a line lyrics, so there's no voice that corresponds to the lyric line, 
then the previous solution has been to insert invisible notes.

The new alternative trick, which IMHO is cleaner, is to align lyrics to a 
devnull context:

\version "2.9.6"

voice = {
        \tag #'music { c''2 }
        \tag #'lyrics { c''4. c''8 }
        d''2
}

lyr = \lyricmode { "foo" "and" "bar" }

<<
  \new Staff \keepWithTag #'music \voice
  \new Devnull="foo" \keepWithTag #'lyrics \voice
  \new Lyrics \lyricsto "foo" \lyr
  \new Staff { c'8 c' c' c' c' c' c' c'}
>>

What happens here, is that a Devnull context is created. Any music which goes 
into that context disappears silently, but lyricsto can still align notes to 
the notes.

Graham: if you agree that this can be useful, then a similar example could be 
useful for the manual. For very complex vocal music, I imagine that this 
devnull trick can be convenient; consider e.g. a duet/dialogue where both 
voices are squeezed into the same staff in a partcombine-ish manner, it 
should be possible to just use tag to say which notes that belong to who.

I have spoke to one person who tried lily but switched to another program 
because it was too difficult to enter such music.

-- 
Erik