Should we use notes accordingly to its key signature or its cadence?
I might be asking something stupid, I haven't complete my music theory basics yet after all..
For the first image, should I use B Double Flat or A Natural? Which one is fundamentally correct? There's no B Double Flat in G Flat Major/E Flat Major so it's troubling me.
As for the second one at Bar 37, should it be E Double Flat & F Flat or D Natural & E Natural on the left hand? What about the right hand, should the main vocal (red arrow) be B Double Flat or A Natural?
The song I'm arranging is this from a game, though I'm arranging its Game Size version and not the full version : https://www.youtube.com/watch?v=hee0-6PloZ4