\version "2.19.36"

\paper {
  page-breaking = #ly:one-line-breaking
  right-margin = 0\cm
  ragged-last = ##f % doesn't have any effect
  indent = 1.5\cm
  %indent = 2.5\cm
}

\score {
  <<
    \new Staff \with {
      instrumentName = "Voice"
    } {
      c'' c'' c'' c''
    }
    \new PianoStaff \with {
      instrumentName = "Piano"
    }
    <<
      \new Staff { c' c' c' c' }
      \new Staff { c' c' c' c' }
    >>
  >>
}