\version "2.19.35"
\language "english"
global = {
  \key c \major
  \time 4/4
}
rightOne = \relative c'' {
  \global
  c c c c
  c c c c
}
rightTwo = \relative c' {
  \global
   e e e_\markup {\whiteout {\fontsize#-3 {ad libitum}}}  e
   e e e e
}
leftOne = \relative c' {
  \global
  g g g g
  e e e e
}
leftTwo = \relative c {
  \global
  c c c c
  e e e e
}
\score {
  \new PianoStaff \with {
    instrumentName = "Pno."
    shortInstrumentName = "Pno."
  } <<
    \new Staff = "right" << \rightOne \\ \rightTwo >>
    \new Staff = "left" { \clef bass << \leftOne \\ \leftTwo >> }
  >>
}