exotic key signatures

[PálBenkő]

when an accidental is not placed at the canonical pitch, it is valid only for 
the first time.  the following excerpt is from no. 99 of Bartók's Mikrokosmos

\version "2.9.13"
\include "deutsch.ly"

\relative c''
{
  \set Staff.keySignature = #'(((0 . 4) . 2) ((0 . 3) . 2))
  \time 3/4

  c8 a gis h a c |
  gis h a4 h8 gis |
  fis
}

gis has a sharp in the second bar (the gis in the first bar and the fis in the 
third bar is unsharped, i.e. the key signature worked for them).

pal