\version "2.13"


global = {
  \key g \major
  \time 4/4
  \set Staff.midiInstrument = #"acoustic guitar (steel)"
  %% tuning: DGDGBE
  \set TabStaff.stringTunings = #'(4 -1 -5 -10 -17 -22)
}

first =  \relative c'' {
  \global

  %% 1
  \repeat volta 2 {
  s16 <g\3\harmonic> <b\2\harmonic> <e\harmonic> ~
  \once \override HarmonicParenthesesItem #'stencil = ##f 
  <e\harmonic> <g,\3\harmonic> <b\2\harmonic> <e\harmonic>
  
  <e\harmonic> <g,\3\harmonic> <b\2\harmonic> <e\harmonic> ~
  \once \override HarmonicParenthesesItem #'stencil = ##f 
  <e\harmonic> <g,\3\harmonic> <b\2\harmonic> <e\harmonic> |
  }
  
  
}

second =  \relative c' {
  \global

  %% 1
  <a'\4\harmonic>4 % right pitch in midi but wrong fret in TabStaff
  <a\4\harmonic>
  <a,\4\harmonic> % right fret in TabStaff but wrong pitch in midi
  <g\5\harmonic> % here I should have put a g,
}



\score {
  \new StaffGroup <<
    \new Staff = "guitar" <<
      \context Voice = "first voice" { \clef "G_8" \voiceOne  \first }
      \context Voice = "second voice" { \clef "G_8" \voiceTwo  \second }
    >>
    \new TabStaff = "tab" <<
      \context TabVoice = "tab first voice" { \clef "moderntab" \voiceOne \first }
      \context TabVoice = "tab second voice" { \clef "moderntab" \voiceTwo \second }
    >>
  >>

  \layout {
    indent = #0
    \context {
      \Staff
      \override StringNumber #'transparent = ##t
    }
  }
  \midi {
    \context {
      \Score tempoWholesPerMinute = #(ly:make-moment 80 4)
    }
  }
}