While the 25th Anniversary Rock and Roll Hall of Fame Concerts were meant to be a celebration of great music, Annie Lennox made sure that the event would be more than just a party. On the show's second night, which was taped in October and premiered on HBO on Sunday, Lennox joined Aretha Franklin onstage wearing a t-shirt that read "HIV Positive" during their performance of the Queen of Soul's 1967 hit 'Chain of Fools.'

Being an HIV/AIDS advocate since visiting South Africa in 2004, Lennox wore the shirt in order to raise awareness about HIV and AIDS. Lennox also started SING, a charity that brings attention to the HIV/AIDS crisis among women and children in South Africa, and recently received the 'Women of Peace Award.'

Lennox's activism doesn't stop there -- she joined the first president of the Republic of Zambia and UK Secretary of Health and spoke to the UK Houses of Parliament about HIV stigma on Monday. Check out the video from the Rock Hall concert below.