Huh, “accomplished pianist” - my Problem are black keys on the piano 
I have made many trance pieces in my youth and used C-Maj in common.
Now I try to develop my skills and wanna use black keys, too (never had piano lessons) 
So in Lake of Tears I startet to use a different scale - and yes… first played the chords with the keyboard (shame on me ^^).
At the moment I am expanding Lake of Tears with more orchestral instruments using solo violins and flutes for a kind of melody line. Also some horns will be involved to fill up things and double basses will support cello staccato.
Chords will stay the same.
I hope I can improve some of my skills in that way - we will see (will post it here).
Best regards
Christian