help with: Cannot find voice

[Alberto Simões]

Hello

I am trying to produce a SATB where S and A share the same staff.


This is my definition:

\score{
        \context ChoirStaff
        <<
                \context Staff = "upper"                        
                        <<
                                \clef treble
                                \context Voice = sop \upperOne
                                \context Voice = con \upperTwo
                        >>
                \lyricsto "sop" \new Lyrics \firstverse                 
                \context Staff = "tenor"
                        <<
                                \clef treble
                                \context Voice = ten \lowerOne
                                \lyricsto "ten" \new Lyrics \secondverse
                        >>
                \context Staff = "bass"
                        <<
                                \clef bass
                                \context Voice = bas \lowerTwo
                                \lyricsto "bas" \new Lyrics \thirdverse
                        >>
                >>
     [...]

Now, lilypond complains with:

4vozes.ly:64:16: warning: cannot find Voice `sop'               
                \lyricsto "sop" \new Lyrics \firstverse                 


Any hint?
Thank you
Alberto


-- 
Alberto Simões - Departamento de Informática - Universidade do Minho
                 Campus de Gualtar - 4710-057 Braga - Portugal