I am quite sure that I am improperly applying the method to make invisible the key signature at the end of a line when the key changes beginning on the next staff.
The code below shows my attempt to use the method in two different manners at several points. I have commented out the non-working code. However, compilation works fine.
I don't actually know which object I am to be overriding and which is proper syntax. I have seen several examples written in the forms I have shown. The ??? is my indication of "Which" object?
harmonies = \chordmode {
c1:maj7 d:m7 e:m7 f:maj7 g:7 a:m7 b:m7.5-
\break d1:maj7 e:m7 fis:m7 g:maj7 a:7 b:m7 cis:m7.5-
}
upper = \relative c' {
\clef treble
\key c \major
\time 4/4
<c e g b>1 <d f a c>1 <e g b d>1 <f a c e>1 <g b d f>1 <a c e g>1 <b d f a>1
%\override ???.keysignature.break-visibility = #end-of-line-invisible
\break
\key d \major
<d, fis a cis>1 <e g b d>1 <fis a cis e>1 <g b d fis>1 <a cis e g>1 <b d fis a>1 <cis e g b>1
}
lower = \relative c,{
\clef bass
\key c \major
\time 4/4
<c e g b>1 <d f a c>1 <e g b d>1 <f a c e>1 <g b d f>1 <a c e g>1 <b d f a>1
%once \override ???.keysignature.break-visibility = #end-of-line-invisible
\break
\key d \major
<d, fis a cis>1 <e g b d>1 <fis a cis e>1 <g b d fis>1 <a cis e g>1 <b d fis a>1 <cis e g b>1
}
\score {
<<
\new PianoStaff <<
%\override PianoStaff.KeySignature.break-visibility= #end-of-line-invisible
\new ChordNames {
\set chordChanges = ##t
\harmonies
}
\new Staff = "upper" \upper
%\once \override Staff.KeySignature #'break-visibility = #'#(#f #t #t)
\new Staff = "lower" \lower
%\once \override Staff.KeySignature #'break-visibility = #'#(#f #t #t)
>>
>>
\layout {
\context { \Staff \RemoveEmptyStaves }
}
\midi { }
}