\layout {
  ragged-right = ##f % use all the space
}
\relative c' {
 \time 6/8 \key g \major
 {
  d8 g a b4 b8 \bar "|" c4. c8 g a b4. \bar "|." 
  \override TextScript.extra-offset = #'(3 . 9) \override TextScript.font-size = #3
  s8-\markup { \whiteout \pad-markup #5.2  "29" }
 }
}