\change Staff in Voice context

[Neil Thornock]

Hi all,
I'm wondering why, in the snippet below, the staff change does not
affect the "mid" voice throughout. It returns to the top staff in the
next measure.

Is there a way to have the staff change affect the entire voice throughout?

%%%%%%%%%%%%%%%%%%%%%%%

aa = \transpose c c' {
   << { c'1 } \context Voice = "mid" { \change Staff = "lo" c4 d e f~ } >>
   << { d'1 } \context Voice = "mid" { f4 e d c } >>
}

bb = { s1*2 }

<<
   \new Staff = "hi" { \aa }
   \new Staff = "lo" { \bb }
>>

-- 
Neil Thornock, D.M.
The recent premiere of ...and a bunch of other stuff:
http://www.youtube.com/watch?v=LQtvPet3k8c
Assistant Professor of Music
Composition/Theory
Brigham Young University