César López is a Colombian musician, composer, guitarist and pianist. In 2003, López founded the Immediate Artistic Reaction Battalion, which involves several musicians and activists seeking alternatives to the violence that has plagued Colombia for many years. The group mainly concentrates its efforts in the city of Bogotá. When informed, it is widely known that the group immediately gathers to play for victims directly affected by the violence within the country. César López is officially a UN Nonviolent Messenger and an Emissary of Conscience for Amnesty International. In 2010, he and his Audio Engineer, Julio Monroy, recorded the album Las Voces del Salado. The album was recorded in the Montes de María with the people of the El Salado hamlet, who were involved in the El Salado Massacre in 2000. López is the creator of the Escopetarra, an AK rifle, a largely symbolic musical instrument. 47 converted into the guitar.