\version "2.14.2"

\score
{
  \new PianoStaff
  <<
    \new Staff = "up"
    {
      \key des \major 
      \time 7/8
      \clef treble
      \set Timing.beatStructure = #'(7)
      
      <<              
	\new Voice
	{
	  \voiceOne
	  \autochange
	  \relative c'
	  {
	    \stemUp
	    {        
	      \bar "|:" 
	      ges8 aes bes c des ees f | 
	      \bar ":|"
	      \cadenzaOn ges1 \cadenzaOff |
	      \bar "|."
	    }
	  }
	}
	
	\new Voice
	{
	  \key des \major 
	  \autochange
	  {
	    \relative c'
	    {
	      \stemDown
	      {
		ges8 aes bes c des ees f | 
		\cadenzaOn ges1 \cadenzaOff
	      }
	    }
	  }
	}
      >>
    }   
    
    \new Staff = "down"
    { 
      \key des \major 
      \clef bass 
    }
  >>
  
  \header
  {
    subtitle = ##f
    subsubtitle = ##f
    piece = \markup{ Two voices with the same notes, the R.H. has stems up and the L.H. has stems down}
  }
}

\score
{
  \new PianoStaff
  <<
    \new Staff = "up"
    {
      \key des \major 
      \time 7/8
      \clef treble
      \set Timing.beatStructure = #'(7)
      
      <<
	\new Voice
	{
	  \voiceOne
	  \autochange
	  \relative c'
	  {
	    \stemUp
	    {        
	      \bar "|:" 
	      ges8 aes bes c des ees f | 
	      \bar 
	      ":|" \cadenzaOn ges1 \cadenzaOff \bar "|."
	    }
	  }
	}
        
	\new Voice
	{
	  \voiceTwo
	  \autochange
	  \relative c
	  {
	    \stemDown
	    {
	      ges8 aes bes c des ees f | 
	      \cadenzaOn ges1 \cadenzaOff
	    }
	  }
	}
      >>
    }
    
    \new Staff = "down"
    {
      \key des \major 
      \clef bass
    }
  >>
}

\header
{
  subtitle = ##f
  subsubtitle = ##f
  piece =
  \markup
  {
    \column
    {
      \justify
      {
	Two voices with notes an octave apart. Now the noteheads are distinct and each voice
	has a single beam connecting all notes in that voice, even when autochange puts the notes into the lower stave.
      }
    }
  }
}