Leigh Blake, 58
A prolific Aids campaigner, Blake is co-founder of the charity Keep a Child Alive, providing treatment and support to families affected by HIV and Aids. She lives in New York with her son
She's a global superstar and I'm cockney as anything. But we both come from the shit-holes of the world – she grew up in Hell's Kitchen and I grew up in east London – so we understand each other.
Ten years ago Bono and I decided to begin advocacy efforts around the Aids epidemic ravaging Africa by reinventing Marvin Gaye's song "What's Going On". We invited loads of superstars to a studio in New York – everyone from Mary J Blige to Michael Stipe – and I said to Bono, "We have to bring Alicia into this." At the time she was a new artist who'd gone straight to number one, and her music really moved me. At the studio she seemed to possess this deep wisdom for her age and she was so open-hearted, and when I told her how so many parents in Africa were dying and orphaning their children, I could see that it really got to her.
We kept in touch and two years later she told me she was going to South Africa on tour. I said, "Mind if I show what the Aids pandemic has done?" She said she'd be honoured to see what was happening. So we went to these clinics, and all these women came up to her and said, "Please help us to get these [antiretroviral] drugs to stay alive and look after our children."
Later, when we were out in the middle of Zululand, she asked, "What do you want to do about this, Leigh?" I said, "I want to get antiretroviral drugs to the poor," and she replied, "If you can figure out a way to do that I'll be with you all the way." It has connected us ever since [as we co-founded Keep a Child Alive].
Fame can change people and have dreadful consequences, and I know there have been great difficulties involved in it for her. But I think Keep a Child Alive has helped her realise there is something much more important than the swirling circle of fame that she dips in and out of. She used her celebrity to save lives, and it's kept her grounded.
Now I see a more mature girl, but not a different girl: she's still kind, sometimes to a fault; she never says a bad word about anyone, so I love saying something bitchy about someone and she has to laugh, even though she's not really of that nature.
Alicia Keys, 30
An award-winning American soul and R&B singer, Keys is co-founder of Keep a Child Alive with Blake. She has sold more than 30 million albums worldwide. She lives with her husband in New York
Anyone who knows Leigh will say that she is one of the most passionate people you will ever meet. She's 5ft 2in, but her spirit is the size of a giant. The way she speaks is inspiring; she's been a warrior for the Aids movement from the start; it's her life and you can see that in her eyes.
I was a young artist just getting started in 2001 when Leigh was putting together a tribute song to talk about the pandemic in Africa. She got all these great people on board and I was excited to be part of something with so many artists, and it felt like an important message. After I recorded my part of the song I sat down in a room with Leigh and she started to tell me about the pandemic. I was only 21 and she was talking to me about things I had no idea about; she got to me because of the way she spoke about it.
Time passed and I went on this crazy world tour; at the end was a concert in South Africa. Leigh was out there too – she has family from there – so we met and she took me to a clinic for young mothers with HIV and their babies. They were so excited to see me, but so desperate. It was crazy to see these women thinking I was their lifeline; I was this little girl wondering what on earth I could do. Leigh did this intentionally, to immerse me in the issue. There's no way you can see their pain and not be moved by it. To see people who deserved to live but couldn't afford the medicines was painful, it showed me what needed to happen and it's what Keep a Child Alive is about. I said to Leigh: if you have the blueprint, then I'm there.
We are yin and yang. I'm the smiler who smooths things over with people; she's the pitbull and she loves to be unleashed. She likes to be outrageous, too, and it's one of the coolest things about her; you have to be outrageous in this work to get people's attention.
I'm in awe of her endless tenacity and her creativity and how she's 100 per cent immersed in being an Aids activist. It's one of the reasons why Keep a Child Alive is so cutting-edge. But it's nice too when we sit down, have a meal and have great chats about other things, such as music. There's lots of super-cool artists that she's put me on to, like this great Thom Yorke track she sent me recently.
I feel so proud of what we've achieved together. No one else has given me what Leigh has: a sense of honour and accomplishment, of being a part of something that's more than my own life.
For more information: keepachildalive.org