Jerry Ragovoy and Bert Berns wrote ‘Piece of My Heart’ — Ragovoy a soul craftsman behind ‘Time Is on My Side’ and ‘Cry Baby’, Berns the writer-producer behind ‘Twist and Shout’ and ‘Hang On Sloopy’. They are the figures the song’s fame obscures most easily: not the famous performer, not the original singer, but the authors whose composition outlived every act that recorded it.