How to increase space between chord names and the fret diagram?

[Stephen Torri]

How can I increase the space between the chord names and the fret
diagrams? At present the names are nearly right on top of the muted or
open string symbols.

Stephen

-----------

\score{
<<
  \new ChordNames \chordmode {
    d
    g
    a
    a:7
  }
  \new Lyrics \lyricmode {
    \markup {\fret-diagram-terse #"x;x;o;2;3;2;" }
    \markup {\fret-diagram-terse #"3;2;o;o;o;3;" }
    \markup {\fret-diagram-terse #"x;o;2;2;2;o;" }
    \markup {\fret-diagram-terse #"x;o;2;o;2;o;" }
  }
 >>
  \layout{
    ragged-right = ##t
    \context{
      \Lyrics
      \override LyricSpace #'minimum-distance = #2.0
    }
  }
}