\version "2.17.95"

%\paper { ragged-right= ##f }

melody = \relative c' {
  c4 c c c | c4 c c c 
  c4 c c c | \override Score.TextScript #'extra-offset = #'(0 . -3)
c4_\markup "melody staff markup"  c c c 
}

words = \lyricmode {
  \override LyricText #'extra-offset = #'(0 . 2)
  \override LyricExtender #'extra-offset = #'(0 . 2)
  la __ _  la __ _ 
  la __ _  la __ _ 
  la __ _  la __ _ 
  la __ _  la __ _ 
}

\score {
  <<
    \melody
    \addlyrics \words
  >>
}