Polyphonic scores consist of many staves. These staves can be constructed in three different ways
\new GrandStaff
\relative <<
\new Staff { c1 c }
\new Staff { c c }
>>
\new StaffGroup
\relative <<
\new Staff { c1 c }
\new Staff { c c }
>>
\relative <<
\new Staff { c1 c }
\new Staff { c c }
>>
The bar lines at the start of each system are
SystemStartBar,
SystemStartBrace, and
SystemStartBracket. Only one of these types is created
in every context, and that type is determined by the property
systemStartDelimiter.
This page is for LilyPond-2.4.5 (stable-branch).