The face of Madeleine McCann was among more than 10,000 images held up at Wembley to raise awareness of the tens of thousands of children who go missing every year in the UK.
Members of the Rock Choir, a community singing phenomenon that is sweeping the country, filled the London stadium with posters of some of the 100,000 children who go missing each year.
The move comes after Prime Minister David Cameron told Kate and Gerry McCann their ordeal was "every parent's worst nightmare" as Scotland Yard pledged to lend its "particular expertise" to the search for their daughter.
Madeleine went missing aged three on holiday in Portugal in May 2007.
Caroline Redman Lusher, director of the Rock Choir, said: "If we can help just one missing child be brought home to safety, it will all have been worthwhile."
Martin Houghton-Brown, chief executive of Missing People, which helped organise the event, said: "By actively joining the search for missing children, and raising funds for the search to continue, Rock Choir has created a truly innovative partnership."