My "come to Jesus" moment on these themes came back when I heard the originals of "Hound Dog" by Big Mama Thornton, "That's All Right Mama" by Arthur Crudup and "Mystery Train" by Junior Parker, side-by-side with Elvis Presley's versions. Quite a major revelation. So much is told through the voice, how the voice interprets a lyric. I dare say that you haven't heard "Hound Dog" until you've heard it sung by its composer, Big Mama Thornton. The song takes on multiple dimensions absent from Presley's interpretation.