vertical alignment & inversion of horizontal brackets

[pls]

Hey all,

today I tripped over a command for typesetting horizontal brackets (\[ \]) 
which doesn't seem to be covered in the manuals. (At least I didn't find it.)

How can I invert and change the vertical alignment of these horizontal 
brackets? (I'd like to place them below the staff.)

\version "2.15.23" % on Mac OS X
{ \[ c''2 c''2 \] }

Thanks for any hint!
patrick