\score {
  <<
    \new Staff=StaffI <<
      \new Voice=AAAA \relative c'' {
	\set Score.midiChannelMapping = #'staff
	\key g \major
	\time 6/8
	d4 b8 c4 a8 | d4 b8 g4 r8
	\time 4/4
	\partcombine { c4 d e f | g a b c } { c4 d c d | e8 f g a r2 }
      }
      \new Lyrics=LyricsI \lyricsto AAAA {
	Girls and boys come | out to play,
      }
    >>
    \new Staff=StaffII \new Voice=BBBB \relative c'' {
      \key g \major
      \time 6/8
      d4 b8 c4 a8 | d4 b8 g4
    }
  >>
  \layout {}
  \midi {}
}