Page formating for book layout

[steve]

  Howdy!

            I have a set of variations (BWV 988) that I have transcribed
and engraved
with lilypond version 2.16.2. It is printed on both sides of the page and
reads like a
book.  I have a \bookpart for each variation. Each variation starts on the
left page
and has  a title and other custom \header stuff.  Each variation is either on
2 pages or 4 pages. I want the top system on the right hand page to line
up with
 the top system on the left page when space allows. How to do this? I simply
want to set the top-margin somehow only on these pages... is this possible
without
messing up top-margin on the "title" page? Or what is the correct way to
do this?

         thanx - steve