Weird key sig accumulation

[Simon Albrecht]

Hello everybody,

I’ve built some music functions to handle a large, multi-section piece, 
and ran into a strange problem, which I could boil down to the attached 
example.
If the concat-part function is called on the \key expression multiple 
times in parallel, the \key expressions are accumulated in a way I’ve 
never seen before. Why would that be?
The original piece is in five parts, and having A sharp major with ten 
sharps pop up on a score by di Lasso was somewhat funny :-)

Best, Simon

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