\include "extractMusic.ily" % http://lsr.dsi.unimi.it/LSR/Item?id=542
\include "tagging.ily" % http://lsr.di.unimi.it/LSR/Item?id=871

Aphrase = {
  c'4 d' e' f'
  g' a' b' c''
  c'' b' a' g'
  f' e' d' c'  
}

\score {
  \new Staff {
    \extractBegin { \repeat unfold 3 \Aphrase } s1*11 % copy first 11 bars
    d'4 f' e' c' % 12th bar
  }
}

Aphrase = {
  c'4 d' e' f'
  g' a' b' c''
  c'' b' a' g' 
  <<
    { f' e' d' c' } % 4th bar and 8th bar
    \tag #'lasttime { d'4 f' e' c' } % 12th bar
  >>
}

\score {
  \new Staff \taggedRep #'firsttime #'lasttime 3 \Aphrase
}