- \set Staff.keySignature = #'(((1 . 2) . 1) ((0 . 3) . -1))
- f8 a c e
- \set Staff.keySignature = #'(((1 . 2) . -1) ((0 . 4) . 2))
+ \set Staff.keyAlterations = #`(((0 . 3) . ,FLAT) ((1 . 2) . ,SHARP))
+ f'8 a c e
+ \set Staff.keyAlterations = #`(((0 . 4) . ,DOUBLE-SHARP) ((1 . 2) . ,FLAT))