Thanks Stan. I've not solved the "partial8" but have had a quick play. I think I'd need to expand things a touch to this for any purpose I might have to get midi output as well?

  \version "2.18.2"
  \header {
        encodingdate = "2018-06-19"
        title = "The Kesh Jig"
        subtitle = " "}
        
        voicedefault = \relative d' {
         \key g \major \time 6/8
          \repeat volta 2 {
         \partial8
              d8 | g4.^"~"^"G" g8 a b | a ^"D" b a a b d | e ^"C" d d g^"G/B" d d | e^"Am" d b d^"D7/F#" b a \break
              g4.^"~"^"G" g8 a b | a^"D" b a a b d | e^"Am" d d g^"G" d b | a^"D/F#" g fis g4^"G" } \break
         \repeat volta 2 {
         \partial8
              a8 | b4.^"~"^"Em" d8^"G" b d | e^"C" g e d^"G" b a | b4.^"~"^"Em" d8^"G" b g | a^"D7" b a a g a | \break
              b^"Em" a b d^"G" b d | e^"C" g e d^"G" b d | g^"C" fis g a^"D7" g a | b^"G" g fis g4 }                 
         }
  \score{
      <<
  
          \context Staff="default"
          {
              \voicedefault 
          }
  
      >>
          \layout {
          }
          \midi {}
  }