stem1 = \notes \relative c' \context Voice = stem1 {
<c4-\arpeggio-\f g' c> \stemDown g'8.b,16 s2
}

stem2 = \notes \relative c' \context Voice = stem2 {
s4 \stemUp g8. b,16 c8 r <e'8. g> <f16 a>
}

stem3 = \notes \relative c' \context Voice = stem3 {
c4 g8. b,16 \autochange Staff {c8 c' c, c'}
}

\score {
	\context PianoStaff \notes <
		\context Staff = up < \time 2/2
			\stem1
			\stem2
		>
		\context Staff = down < \time 2/2 \clef bass
			\stem3
		>
	>
	\paper { }
}