Re: new key signatures

[Gilles]

> 
> Is it possible to create 'new' key signatures?  I mean, I desire to be able
> to make key signatures for my own scales.  For instance, here is a favorite
> [...]
> Is this possible?

Yes, see:

  http://lilypond.org/doc/v2.7/input/regression/lily-1122588603.ly

With (cf. example in the above page), if IRC:

    \set Staff.keySignature = #'(((1 .  2) . 1) ((0 . 3) . -1))

                                   ^    ^    ^
                                   |    |    |
                                 octave |    |
                                       note  |
                                           offset in units of quarter-tone

Best,
Gilles