unusual key signatures in lilypond

[Michael Vanier]

Hi,

I'm typesetting some music with an unusual key signature.  This used to be
done using (say):

    \keysignature c g;

but this no longer works (BTW why was it removed?).  Now you're supposed to
do this (e.g.):

    \property keySignature = #'((2 . -1) (4 . -1) (6 . -1))

(BTW can anyone explain the syntax to me?) but when I do I get this error
message:

tune1.ly:147:44: error: parse error, expecting `'.'':
                    \property keySignature =
                                             #'((2 . -1) (4 . -1) (6 . -1))

This is using the latest development version of Lilypond (1.3.119).

Thanks,

Mike