SystemStartBracket/Brace

[address@hidden]

Hello, All--

To start, i'm using LilyPond 2.18.2.  To keep this short, here is how i've set up my score:

\score {

  \new GrandStaff
    <<
    \set GrandStaff.connectArpeggios = ##t

       \new PianoStaff
       \set PianoStaff.connectArpeggios = ##t
         <<
            \new Staff = "upper" \upper
            \new Staff = "lower" \lower
         >>

       \new Staff = "feet" \feet

    >>

}

Many will recognize this as a modification of the "organ template" in section 3.4.3 of the Learning Manual.  i put the entire system in a GrandStaff because i found it the only way to connect an arpeggio across all three staves.

But getting to the point:  i would like the SystemStartBrace of the GrandStaff to span only the top two staves.  When i remove the System_start_delimiter_engraver from the GrandStaff and put it in the PianoStaff, i get no SystemStartBrace at all.  If i try \override GrandStaff.SystemStartBrace.collapse-height = #10, the SystemStartBrace never changes size, still spanning over all three staves.

The last option has led to some behaviour that i just don't understand.  i can set the collapse-height number to as large as 21, and the brace remains.  If i set the number to 22, the brace disappears.  Given that the total number of staff lines is 15, i don't see how that is conistent with this statement:  % Must be lower than the actual number of staff lines.  The quote came from the section of the Snippets manual on how to display a bracket with only one staff in a system.  Can i assume that the collapse-height property only works with one staff in a system, as per the snippet?  If not, then why did the property behave as it did in my override?  After all, both 21 and 22 are greater than 15, so the brace should have disappeared when i set the collapse-height property to 16.  As i said, i don't understand, no matter how much i read.

One more thing.  i nested all brackets and braces, defining the "feet" staff as a single staff in a system (as per the snippet mentioned above), attempting to get everything to print.  Only the brace for the GrandStaff and the bracket for the "feet" staff printed.  The brace for the PianoStaff did not print.  In fact, in my setup, it never prints--ever.  i even changed PianoStaff to StaffGroup, specifying a bracket instead of a brace, and still the bracket wouldn't print.  It appears to be ignored in the nesting procedure.

So, after about fifteen hours struggling with this, i've taken to the group.  i apologize for the length, but i wanted to be as thorough as possible.  i appreciate any and all help not just solving this problem, but also understanding what's happening.  Thank you, much!

bill