In musical pieces there’s a key that’s home (the tonic), and whenever you leave home you want to go back, if it just ends there then you feel you’re left hanging. But in certain pieces they treat a different key as home, surround it with chords that make it feel like home. It’s like the plot of a story: establish somewhere that’s home, then some conflict where you unsettles that sense of home, then try to find your way back…
(from Naomi)