Birkin, who recorded “Je T’aime … Moi Non Plus” with Gainsbourg while they were partners and who kept on singing songs he wrote for her after they broke up, says that many of his songs were rooted in classical music. “He was a pianist at a bar in Le Touquet [a seaside town in northern France], and his father was a classical musician — it was from his upbringing that he knew so much about classical music. Brahms was ‘Baby Alone in Babylone.'”