<<
  \new Staff \with {
    instrumentName = "Alto Flute in G"
    shortInstrumentName = "Flt."
  } \relative {
    f''2 g4 f \break
    g4 f g2
  }
  \new Staff \with {
    instrumentName = "Clarinet"
    shortInstrumentName = "Clar."
  } \relative {
    c''4 b c2 \break
    c2 b4 c
  }
>>

\layout {
  indent = 3.0\cm
  short-indent = 1.5\cm
}