Please note that this problem (and the "solution" of moving the tie
engraver to the staff context) has been discussed several times before
on the mailing list, including the following threads:
http://lists.gnu.org/archive/html/lilypond-user/2007-01/msg00359.html
http://lists.gnu.org/archive/html
Wilbert Berendsen writes:
> Agreed. Even when explicitly instantiating voices it remains necessary to use
> them for e.g. cross-voice ties. Easy cross-voice ties would be very nice, as
> they occor very often in keyboard music. This is an example that works:
>
> \layout {
> \context {
> \
Op zondag 08 november 2009 schreef David:
> Hm. Maybe ties should work at the staff level as fall-back. Or even
> just explicitly. Wouldn't it be nice to be able to say ~~ and have the
> tie work staff-level? The current voice jigglery-pokery is not
> particularly nice, and it gets worse when
