I love every single thing Nina Simone did! Wikipedia says
Her musical style arose from a fusion of gospel and pop songs with classical music, in particular with influences from her first inspiration, Johann Sebastian Bach,and accompanied with her expressive jazz-like singing in her characteristic low tenor. She injected as much of her classical background into her music as possible to give it more depth and quality, as she felt that pop music was inferior to classical. Her intuitive grasp on the audience-performer relationship was gained from a unique background of playing piano accompaniment for church revivals and sermons regularly from the early age of six years.