There are chords, and then there are cords. How do you keep them all separate? With great difficulty, because the two words have a somewhat incestuous history, and the spelling chord, to boot, represents two different words. Three or more notes sounded together is a chord; that's one word. A line connecting two points on a circle is a chord; that's another word. Vocal cords and spinal cords are different things, though anatomical structures sometimes use the spelling chord, and you can use your vocal cords to produce chords. Just so you know.