 Following the seven performances on the Joshua Tree Tour , U2 did not perform " Mothers of the Disappeared " until 1998 , on the fourth leg of the PopMart Tour . It was played at three concerts in Argentina and once in Chile , concluding all four shows . Bono sang " el <unk> <unk> " at the end of each performance . The first rendition was on 5 February 1998 in Buenos Aires , where it was performed with the Madres accompanying them on stage . The song was played by just Bono and the Edge and was set against footage of the Madres on the video screen . At the conclusion of the song , the band members faced the Madres and applauded , an act in which the rest of the audience joined . Part of the performance was later included on the television documentary Classic Albums : The Joshua Tree . 
