addlyrics and lyrics positioning

[Tom Cato Amundsen]

Below is a part of a choral arr I am making. Are there some 
property I can set to get the lyrics above the staff?

I need to \addlyrics the lyrics to the bassI voice because
that voice is the only voice that has the correct rhythm.

\score{
 <
   \context Staff=i<
    \context Voice=i\tenorI
    \context Voice=ii\tenorII
   >
   \context Staff=ii<
    \addlyrics \context Voice=iii\bassI <
      \context Lyrics=li\versI
      \context Lyrics=lii\versII
     >
    \context Voice=iv\bassII
   >
 >
}
-- 
Tom Cato Amundsen <address@hidden>
GNU Solfege - free eartraining, http://www.gnu.org/software/solfege/