When Grace Idowu's 14-year-old son David was stabbed outside her home in Southwark in 2008 he became the 19th victim of knife crime in London that year. Grace and her husband Tim said in a statement to the court which tried his killer, "The knife which pierced David's heart will keep the wounds open in our hearts forever."
But Grace has since met David's murderer and forgiven him. In 2009 the David Idowu Foundation was set up. She's now made it her life's mission to bring young people in her community together to prevent future attacks.
Her latest initiative is the David Idowu Choir which is taking young people from schools across Southwark and getting them to sing together, regardless of their background, faith or race. Grace says, "Music is so powerful... it's one way to bring unity. When you are singing you're just speaking one language."
The choir is being partially funded by a grant from the Near Neighbours programme. It's been set up to provide local communities with the resources they need to bring together those of different faiths and none, as well as those of different ethnic backgrounds. To find out more, or to apply for a grant,check the website: http://www.cuf.org.uk/near-neighbours
Here, you can listen to snippets of the choir and a conversation between Grace and Andy Walton from Near Neighbours.