programming error: moment not increasing

[Sebastian Canagaratna]

Hi:
  I have seen some comments about this in Google, but they do not solve my problem.
I was trying to see whether I could code SATB hymns which sometime have only one voice, say tenor
with accompaniment, then SATB, then only bass and accompanimebt, etc.

  I can write these part in different scores, but the midi comes in different files. I give below an simple example
of my attemps to do this in one score; all attempts come up with the above error, and the SATB part is not written 
at all. 
 
I started off with 4 measures in each section and I think that was reproduced OK except that the end of the tenot
section had a common time signature.  With four measures in the teno and the SATB section, the problem comes up.

Is this a bug, or am I doing something wrong?

Thanks for any suggestions.


Sebastian Canagaratna 


\version "2.12.3"
global = {
   \key c \major
   \time 4/4
   }


tenorIMusic = \relative c'' {
     c4 c c c c c c c c c c c c c c c  }
tenorIUMusic = \relative c'' {
     c4 c c c  c c c c c c c c c c c c  }
tenorILMusic =  \relative c' {
     c4 c c c  c c c c c c c c c c c c   }
sopranoMusic = \relative c'' { c4 c c c c c c c c c c c c c c c  }  
altoMusic = \relative c' { c4 c c c  c c c c c c c c c c c c }
tenorMusic  = \relative c' { c4 c c c c c c c c c c c c c c c }
bassMusic = \relative c { c4 c c c c c c c c c c c c c c c }
tenorIWords = \lyricmode { a a a a a a a a a a a a a a a a } 

\score {
{
  
   { <<
      \new Staff = "tenorI" {
         <<
      \new Voice = "tenori" {
            \global  
        \clef treble
        \tenorIMusic   }
          \new Lyrics \lyricsto "tenori" \tenorIWords
            
     >>
        }     
        \new PianoStaff = "tenorIacc"
           { <<
            \new Staff = "tenorIU" {
                \global
                \clef  treble  
                    \tenorIUMusic 
          } 
                 \new Staff = "tenorIL" {
                 \global
             \clef  bass
                 \tenorILMusic  }
             >>

             }
     
     
     >> 
  } 
  

{ <<
     \new ChoirStaff = "satb" {
         << 
          \new Staff = "soprano" {\global \clef treble 
                          \sopranoMusic }
           \new Staff = "alto" {\global \clef treble 
                          \altoMusic }
                \new Staff = "tenor" {\global \clef bass 
                          \tenorMusic  }
           \new Staff = "bass" {\global \clef bass
                          \bassMusic  }
            

          >>

      }
     \new PianoStaff = "piano" {
          << \new Staff = "Upper" {\global \clef treble
             \relative c'' { c4 c c c} 
              }
            \new Staff = "lower" { \global \clef bass
                  \relative c { c4 c c c } 

              }
         >>
   
     }

 >>
 }
 
}

}