Cross staff notation

[Helge Kruse]

Hello,

I want to write a piece that has a lot of cross staff notes. I have to switch the staff and keep care for the stemp direction. This 
is a repeated task and annoying.
How can I manage this in an easy and error proof way? I attach the original to 
show how it should look like.

Best regards,
Helge


\version "2.10.4"
\include "deutsch.ly"

upperHarp = \relative c' {
\clef treble  \key d \major  \time 4/4
fis'2 e | d cis |
}

lowerHarp = \relative c {
\clef bass  \key d \major \time 4/4
\stemUp d8 a' d \change Staff = u \stemDown fis \change Staff = l \stemNeutral
a,, e' cis' \change Staff = u e \change Staff = l |
h, fis' h \change Staff = u d \change Staff = l |
fis,, cis' a' cis |
}

\book
{ \score
{
 { <<
  \new GrandStaff
  <<
   \new Staff = u \upperHarp
   \new Staff = l \lowerHarp
  >>
 >>
 }
 \layout { }
}
}

xstaff.JPG
Description: JPEG image