Try Rune's suggestion from
http://lists.gnu.org/archive/html/lilypond-user/2007-12/msg00147.html
which solves the same problem without any need to manually specify the
position.
Rune's tip is a great start because it makes all cross-staff beams sit at the same vertical position.
Is there a way to get "normal" (noncrosss-staff) beams to likewise sit at that same vertical position?
(IOW, I'm looking for both flat and vertically aligned; Rune's #+inf.0 gets flat ... now for the vertically aligned part?)
%%% BEGIN TAKE 2 %%%
\version "2.11.34"
\new PianoStaff <<
\new Staff = RH {
\time 9/8
\override Staff.VerticalAxisGroup #'minimum-Y-extent = #'(-10 . 20)
\override Stem #'direction = #down
\override Beam #'damping = #+inf.0
c'8 [
c'8
\once \override Stem #'direction = #up
\change Staff = LH
c'8 ]
\change Staff = RH
c'8 [
\once \override Stem #'direction = #up
\change Staff = LH
c'8
\change Staff = RH
c'8 ]
c''8 [ % how to make this one sit at the same vertical pos?
c''8
c''8 ]
}
\new Staff = LH {
\clef bass
s1 * 9/8
}
>>
%%% END %%%