That's why I loved Dinah Washington. She sung jazz, but they called her the Queen of the Blues. She had the control and sophistication of jazz in her note selection and how to attack a song or certain lines, but then attacked it with a painful force of blues behind it. That's why I admired her so much, because of that versatility.
Soul music is true to its name. It's music that connects to your soul, your spirit. When music resonates with people's spirit like that, when people can emotionally connect with something or it helps to heal them, transform them, that never goes out of style. People will always need something to relate to.