Yet another voice and ties problem

[Knute Snortum]

I have another problem with voices and ties.  basically, I have octaves moving and an inner voice staying still.  I'd like the upper notes of the octaves to be tieUp and the lower notes to be tieDown.  But I can find no way to act on the lower and upper note independently of each other and still share a stem.

​Here is the sample code:

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

\version "2.18.2"

\language "english"

global = {

  \key gs \minor

  \time 6/8

  \clef treble

}

\new Staff {

  <<

    \new Voice {

      \relative c'' {

        \global

        \voiceOne

        % | <a' a'>4. ~ ( q8 <gs gs'>8 <fs fs'> )

        % \once \override Tie.rotation = #'(180 0 0)

        <<

          { \tieUp a4. ~ a8 gs fs }

          { \tieDown a'4. ~ a8 gs fs }

        >>

      }

    }

    \new Voice {

      \relative c'' {

        \global

        \voiceTwo

        \override NoteColumn.force-hshift = #1.4

        <ds fs>2.

      }

    }

  >>

}

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

Knute Snortum

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