\unfoldRepeats and \repeat with midi output in lilypond

Question

I have a piece of lilypond code here:

trebleNotesOne = {
    \unfoldRepeats { 
        \repeat volta 2 {
            r8 a'16 b'16 c''8 b'16 c''16 d''2 | 
            r8 b'16 a'16 b'8 a'16 g'16 f'2 |
        } 
    }
}

bassNotesOne = { 
    \clef bass  
    \unfoldRepeats { 
        \repeat volta 2 {
            a8 b8 c8 d8 a8 b8 c8 d8 | 
            a8 b8 c8 d8 a8 b8 c8 d8 |
        } 
    }
}

\score {
    \new GrandStaff
    <<
        \new Staff << \trebleNotesOne >>
        \new Staff << \bassNotesOne >> 
    >>
    
    \layout {
        ragged-right = ##t
    }
    \midi {}
}

I want both the repetition notation (\repeat volta 2) printed in the sheet music pdf, and for the midi file generated to contain repeated plays.

The above code prints:

But I want in pdf:

with midi repetition.

Answer 1

To get repeats to display in proper notation in the PDF, but to also unfold in the MIDI, you will actually need to make two score blocks.
One score block with a \layout{}, and one with a \midi{}.
Put the \unfoldRepeats command in the midi score block.
(see 3.5.6 Using repeats with MIDI)

Something like this:

trebleNotesOne = {
    \new Staff
        \repeat volta 2 {
            r8 a'16 b'16 c''8 b'16 c''16 d''2 | 
            r8 b'16 a'16 b'8 a'16 g'16 f'2 |
        }
}

bassNotesOne = {
    \new Staff 
        \clef bass  
        \repeat volta 2 {
            a8 b8 c8 d8 a8 b8 c8 d8 | 
            a8 b8 c8 d8 a8 b8 c8 d8 |
        }
}

theMusic = {
    \new GrandStaff
        <<
            \trebleNotesOne
            \bassNotesOne 
        >>
}

%% PDF SCORE
\score {
    \theMusic

    \layout {
        ragged-right = ##t
    }
}

%% MIDI SCORE
\score {
    \unfoldRepeats { 
        \theMusic
    }
    \midi { }
}