LilyPond: Setting Vertical distance for PianoStaff

Question

I'm trying to engrave a piano song. I have read the LilyPond manual over and over and tried several things:

I want the spacing between the scores to be bigger. Minimal not working example is

\new PianoStaff
  \with {
    \override VerticalAxisGroup #'default-staff-staff-spacing #'basic-distance = #10
  } 
  <<
  \new Staff \relative c'' {
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
  }

  \new Staff \relative c' {
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
  }
>>

I am using LilyPond 2.16.2.

Does anyone know how to to this?

Answer 1

I found the answer: The MWE is

\paper {
  system-system-spacing #'basic-distance = #20
}

\new PianoStaff
  <<
  \new Staff \relative c'' {
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
  }

  \new Staff \relative c' {
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
  }
>>

But maybe my badly formulated question and the nice answer of @Dave will be helpful to someone.

Answer 2

This works for 2.18 (can't easily check 2.16), obtained from here in the documentation

<pre>
\new PianoStaff
 \with {
   \override StaffGrouper.staff-staff-spacing.basic-distance = #44
  } 
  <<
  \new Staff \relative c'' {
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
  }

  \new Staff \relative c' {
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
    c c c c | c c c c | c c c c | c c c c |
  }
>>
</pre>