\version "2.18.2"
%%\version "2.19.36"
\language "english"

\header {
  tagline = ##f %% Lets me crop the snippet for posting
}

%% the structure of the piece
global = {
  \key d \major
  \time 4/4
  s1 % M 1
  \time 2/4
  s2 % M 2
  \time 4/4
  s4 % ... % M 3
  %% ...
  %%\bar "|."
}

%% the melodic lines
sopi = \relative {
  e''4 d8 e16 c!~ c4 b8 c16 a16~ | % M 1
  a4 g16 fs8. | % M 2
  %% ...
}

sopii = \relative {
  g'4 g8. e16~ e4 d8. d16~ | % M 1
  d4 d | % M 2
  %% ...
}

%% the lyrics
sopitext = \lyricmode {
  Oo...
}

sopiitext = \lyricmode {
  Ah...
}

%% the layout
\score {
  \new ChoirStaff <<
    \new Staff = staff <<
      \clef treble { \global }
      \new Voice = vsi { \voiceOne \sopi }
      %%\addlyrics \with { alignAboveContext = staff } { \sopitext } % 2.19.36 syntax
      \new Lyrics \with { alignAboveContext = staff } \lyricsto vsi { \sopitext }
      \new Voice { \voiceTwo \sopii }
      \addlyrics { \sopiitext }
    >>
    \new Staff = staff <<
      \clef bass { \global }
      %% ...
    >>
  >>
  \layout { }
  \midi{ }
}