Overlapping Horizontal Brackets

[Monk Panteleimon]

Hello.
I am preparing a musicological document in which one figure shows
overlapping tetrachords. I want to do \stopGroup and immediate \startGroup (with
the bracket on the other Y side of the staff) on the same note, but LP
won't do it. It looks like analysis brackets can be nested, but not
overlapping.

What's the best way to go about this? I found several things in archives
about drawing brackets as spanners without HorizontalBracket engraver,
but is there a simpler way to just override the Horizontal
Brackets behavior?

Here's my minimal example:

\version "2.11"
\header{title="Overlapping Tetrachords" }
\score {
        \relative c''
        {  \set Score.defaultBarType = ""  
        \override Score.HorizontalBracket #'bracket-flare = #'(0 . 0)
        \override Score.RehearsalMark #'direction = #-1
        g1\startGroup \mark\markup\tiny{1} a \mark\markup\tiny{1} b 
\mark\markup\tiny{1/2,etc.} 

%The important part:        
        c\stopGroup % \startGroup on the same note is what I want to do, but 
can't
        % with Bracket on top like this:
        \once\override Score.HorizontalBracket #'direction = #1 
        d\startGroup^\markup{I want this bracket to start on the C} e 
f\stopGroup }
      

\layout{ ragged-last = ##t
        \context { \Staff \consists "Horizontal_bracket_engraver" }
        }
}

I also couldn't find a way to get the \mark inside the bracket instead
of outside, but that's secondary.
Thank you.

-- 
Monk Panteleimon
Hermitage of the Holy Cross
Wayne, WV, USA
address@hidden

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