\version "2.19"

<<
\new Staff \relative c'' { a4 a a \key a \major s a a }
\new Staff \relative c'' { a4 a a \key a \major a a a }
>>

<<
\new Staff \relative c'' { a4 a a \bar "" \key a \major s a a }
\new Staff \relative c'' { a4 a a \key a \major a a a }
>>

<<
\new Staff \relative c'' { a4 a a \bar "||" \key a \major s a a }
\new Staff \relative c'' { a4 a a \key a \major a a a }
>>