repeat bars in all staves except one

[Kieren MacMillan]

Hello all,

In the following [minimal] snippet,

\version "2.19"

global = {
  \time 4/4
  s1
  \repeat volta 1 { s1 }
}

\score {
  <<
    \new RhythmicStaff << \global { a1 a } >>
    \new Staff << \global { c''1 c'' } >>
  >>
}

I would like to have the RhythmicStaff *not* have repeat barlines, e.g., maybe 
just “||” double bars.
What’s the easiest way? I can’t seem to find the right incantation…

Thanks,
Kieren.
________________________________

Kieren MacMillan, composer
‣ website: www.kierenmacmillan.info
‣ email: address@hidden