Annie Lennox

After hearing Nelson Mandela describe the HIV pandemic in Africa as a "genocide," Lennox took up the cause, forming the SING organization to raise money and awareness. She was named UNAIDS Goodwill Ambassador, and in 2010 gave a TED talk called "Why I am an HIV/AIDS activist."

She and Dave Stewart were a couple when they formed a group called The Tourists in 1977, but split up before they formed the Eurythmics in 1980. Their relationship remained complicated, and they often used songs and interviews as a form of therapy. In 1988, she said of their relationship, "It isn't physical anymore, but it is romantic."

Lennox is one of the most popular British female artists of all time. Including her work with Eurythmics, she's sold over 80 million albums worldwide.