Analysis brackets?

[Claudia]

Hi, I need to draw several superimposed -- although not nested -- 
brackets in order to evidence two 
melodic overlapping structures for teaching purposes. Does 
anyone knows how to do it?

I've tried Analysis brackets but the groupings are presumed nested 
and so, the group openings and 
closings are interpreted as in a heap.

I'm looking for something like:
\openGroup1 c d e f \openGroup2 g a b c \closeGroup1 d e fis g \closeGroup2


Thanks!
Claudia