context inheritance?

[Kieren MacMillan]

Hi all,

I want to define a "tree" of contexts like

\Staff
    \PianoSingleStaff
        \PianoSingleStaffRH
        \PianoSingleStaffLH
    \ReductionSingleStaff
        \ReductionSingleStaffRH
        \ReductionSingleStaffLH

and then, in my music (e.g., in a reusable variable), I'd like to say

  \change Staff …

or

  \override Staff …

and have any of the seven contexts listed above respond to that command.

So far, my attempts (using \alias, etc.) have failed. This isn't a case, I 
think, where a minimal example will help — either it's possible to do this (and 
thus probably easy to describe how), or it's a non-Lilypond philosophy, and I 
should give up on it. Any help would be appreciated.

Thanks,
Kieren.