Hello, I am having a discussion with a colleague wether a key change should be preceded with a double barline yes or no.
In E. Gould she says double barline only when also a new musical section (otherwise single barline).
In Ted Ross from 1978 it shows the double barline as standard.
What would be the best for notating 18th century music?
Example Ted Ross:
Example Elaine Gould:
If I’m doing a part replacement I copy what is already in the score etc.
Otherwise, Gould.
The adverb in the Ross is key: “traditionally”. It’s a convention that gradually fell out of use. However, if you’re doing 18th century music, it’s very much an editorial decision to modernize that aspect of the notation or not. I would keep it. Confront with the manuscript and contemporary sources of the material you’re working with.
If you have a look at the manuscript, here:
This is, how Dorico handles it:
I don’t like the double double-barline either… There was a thread in 2016 about this.
If you want to change the automatically created double barline at a key change, select the double barline and either click on the “normal barline” button or enter “|” in the + popover.
My problem is with the additional barline created at the confluence of repeat and key change.
Estigy,
your suggestion does not work 
Because I can not select the double barline on its own.
The start repeat barline will be highlighted, too.
So if I then change the barline to a normal barline, the repeat barline will be lost 
key change example.dorico.zip (667 KB)
I have to admit, I did not try it in combination with a repeat bar 
… never mind (-;
I’d like the barline then the key then the repeat dots (for most things…)
It’s not out of use yet, although there’s certainly been a shift towards single barline before key changes in recent decades.
Personally, I prefer the double barline as a visual aid before key changes in classical music which otherwise isn’t sprecifically sectionalised. Otherwise, in the relatively rare event of a key change in the middle of a specified section, I use single barlines to avoid any confusion with regard to the form.
In theatre stuff and my own writing, I’ve used thick barlines for structural cues for a long time. This leaves doubles for barlines with dialogue between etc. Thick double barlines are a useful ‘watch out!’ marker.
