4 texidoc ="Polyphonic piano music."
7 upperOne = \notes\relative c'' {
12 upperTwo = \notes\relative c' {
17 lowerOne = \notes\relative c {
22 lowerTwo = \notes\relative c {
28 \context PianoStaff <<
30 \context Staff = upper <<
31 \context Voice = one \upperOne
32 \context Voice = two \upperTwo
34 \context Staff = lower <<
36 \context Voice = one \lowerOne
37 \context Voice = two \lowerTwo