You should actually be able to choose the key signature

[GamemakerX1]

Something I noticed is when I set a sequence to any key, it 'auto corrects' it to what key it 'thinks' it should be. Most of the time this is a problem is when you have lots of off-key notes, so it doesn't detect that it even has a key. Even if you don't choose a key yourself, it still assigns one (if most of the notes fit) but it never does any minor keys! I hope this can be fixed soon. I'm pretty sure this has been the case ever since key signatures were added.

I Feel You man.