i played a second piece , and then a third , and every time my rhythm was on , and i found myself seeing and using new nuances , variations on chords that lent depth and color to the simple pieces i could play - sweet sadness to the minor chords , power to the majors , stresses and resolutions i 'd always heard in my head , but could never express in life , it was almost like someone had opened a door in my head , like they were helping me along .