How to get all Voice-Contexts?

[Thomas Morley]

Hi,

for some engraver I need to look at all Voices, comparing them in some regard.

If I put the engraver in every Voice, then every Voice is processed,
yes, but I can't find a method to compare them.
So I thought the way might be to put the engraver in Score, get the
Voices and do nasty things ...

Though, I can't find a method to select all Voices.

Consider this tiny and boiled down example:

%%%%%%%%%%%%%%%
\version "2.19.32"

get-Voices =
\context Score \applyContext #(lambda (ctx) (display ctx))

\score {
    \new Staff
    <<
      \new Voice = "1" { \get-Voices c''1 }
      \new Voice = "2" { e'1 }
    >>
}
%%%%%%%%%%%%%%%%

How to get all Voices looking down from Score?


Thanks,
  Harm