Annie Lennox has signed up for Nelson Mandela's World Aids' Day concert in December.The former Eurythmics singer will join a host of music stars, including Peter Gabriel, Jamelia, Ludacris, Razorlight and Corinne Bailey Rae, at the former South African President's concert to raise HIV and AIDS awareness in Johannesburg's Ellis Park stadium on December 1. Ludacris said: "It's a shame that after all these years we still have to raise awareness for a disease that continues to infiltrate communities, countries and families. But I am proud to be able to stand by Nelson Mandela, a man of dignity, power, strength and change and one who always leads by example. I hope this concert will be another stepping stone to finding a cure."Annie - who was involved in the first concert in November 2003 - is also doing her own bit to raise awareness of the disease by releasing a new album, 'Songs of Mass Destruction', and a musical project, 'Sing', featuring a single involving 23 top female singers, including Madonna, Celine Dion, Pink and Shakira. She said: "I'd recorded a track, and was trying to think about how to develop it. I just needed to ask some other women who were renowned and successful artists. So I got a generic letter, sent it out to them, and waited to see what would happen."Some weren't available or were too busy, but they were all so sweet and said they'd love to do it."Mandela will announce the full line-up for the World Aids' Day concert on October 29.