"The Singing Nun" refers to Sister Jeanine Deckers, a Belgian nun who gained fame in the 1960s for her musical talent. She recorded the hit song "Dominique," which became a chart-topping success in the United States and other countries. Her unique blend of religious themes and popular music captured the hearts of many. Sister Jeanine's rise to fame led to a brief career in the music industry, but she struggled with the pressures of celebrity. Despite her initial success, she eventually left the convent and faced personal challenges, including financial difficulties, before her passing in 1985.