Positioning lead sheet symbols

To position lead sheet symbols above repeat brackets, override their Y-offsets. Without additional elements the values in the snippet can be used; they may have to be tweaked in a real music context.

\version "2.24"

<<
  \chords {
    c2 g:sus4
    \override Score.ChordName.Y-offset = #2
    f e
    g c
    \override Score.ChordName.Y-offset = #0
    c/g c
  }
  \relative c'' {
    \override Score.VoltaBracketSpanner.Y-offset = #1
    \repeat volta 2 { a4 e c8 e r4}
    \alternative { { b2 c4( d) } { b8 r d4 c2 } }
    c1
  }
>>