Pop music channel MTV announced plans Thursday for concerts in Cape Town and Seattle to mark World Aids Day on December 1. Performers will include Alicia Keys, Missy Elliott, and Dave Matthews, among others. "I hope the global broadcast of the concert encourages young people to understand that HIV/AIDS is preventable," said Grammy Award winner Keys, who will perform during the South Africa concert on November 23. The Seattle concert will be held November 7, with a 90-minute special program covering both shows to air on MTV on World AIDS Day, reaching a potential audience of 2 billion people. MTV is also offering the taped special free of charge to other interested television networks worldwide. The concerts are sponsored by Levi Strauss and the Bill and Melinda Gates Foundation.