President Tony Tan Keng Yam being joined on stage by Mr Timothy Chionh, managing director of the Wild Empire Choral Group, and Ms Ong Chiak Yin, the choral conductor, during the launch of the President's Challenge yesterday. The annual campaign began with a concert organised by Wild Empire at the School of the Arts that raised $22,000. About 50 organisations, including those from family social services and eldercare, will be benefiting from the fund-raising drive.