Hi winternotes,
In order the changes you have made to a midi file to be applied,
you have to go to
Song Creator and make any change you wish(by also calling the Mixing Console)
and afterwards go to
Channel
5 Setup
and press "EXECUTE"!!!
Now you can save your modified midi.
As for the folders:
A folder made by a user can contain several things that the user wants to be in that folder.
Usually for our convenience, we are giving the folder a name like "My Midi Songs" and we are saving ONLY midi files in that folder, so we know where we must search for our midis.
To have access to your midi files you have to press Song Select (top right on your keyboard)
or the letter "A" (beside your screen).
By pressing one of these two buttons the keyboard "understands" that you are searching the folders to find midis.
So in a folder of yours that there are only styles in it,
the keyboard will show you that this folder is empty (of midi files) when you press the letter "A".
But if you press the letter "E" on that same folder, now the keyboard will show that there are styles in it, and it is not empty at all.
So press the appropriate letter each time around the screen, when you want to search your folders for:
Styles(E)
Midi Songs(A)
Multi Pads(I)
Registrations(J)
and voices(F,G,H)