\version "2.20.0"

introduction = \markup {
	\score {
		<<
			\new PianoStaff <<
				\new Staff = "upper" \relative c' { f1 | f | f | }
				\new Staff = "lower" \relative c' { f1 | f | f | }
			>>
		>>
	}
}

\score {
	<<
		\new PianoStaff \with {
			instrumentName = \markup { " " \raise #4 \introduction " " }
		}
		<<
			\new Staff = "upper" <<
				\new Voice \relative c' { f4 f f f8 f | f4. f8 f4 f | }
				\new NullVoice = "singer" { 4 4 4 4 | 4. 8 4 4 | }
			>>
			\new Lyrics \with { alignAboveContext = "upper" } \lyricsto singer { Aaa aa aaa aaaa | aaa aaa aa gnes | }
			\new Staff = "lower" \relative c' { f1 | f | }
		>>
	>>
}

\layout {
	indent = 6.95\cm
}