The following is an open letter to Latin musician Mercedes Sosa sent on 21 July 2008 by the Palestinian Campaign for the Academic and Cultural Boycott of Israel: How can Mercedes Sosa, the quintessentially progressive diva of freedom songs in Latin America, sing in Israel, a colonial and apartheid state whose war crimes have reached new lows, systematically and deliberately destroying Palestinian society and engendering a process of slow ethnic cleansing of the indigenous people of Palestine?