This is something that I asked myself long ago but I didn't have any challenge about it until now.
I'm working on a PC vintage ethnic game, and I'm making Music and SFX.
The soundtrack is big, and it turns to be in different keys each track, so when I have to make SFX with different hierarchy (for example, little things, little power ups, with big and important items and powers, etc.) I found that when I want to make this kind of musical or complex item SFX in one track or another it'll crash to dissonance in some of the levels.
Having this problem I found that I worked for a lot of little games (with for example one track or two) in which I could fit the keys of the SFX and the soundtrack. But in this case I don't know if I have to let the developers code some kind of fade (as a side chain with the music) when the SFX is going on or If it has to be the music down, or if I have to change the esence of the sound design (maybe making inharmonic complex item sounds?).
Thanks in advance, I'll try to figure it out but If you have some advice I'll learn something more.
Best regards for all,