The song, which praises a friendship that has overcome many difficulties, became particularly popular after a children's choir sang it for Pope John Paul II on his 1979 visit to Mexico.
[5] On 30 January, the Pope was scheduled to visit the Instituto Miguel Ángel, a private Catholic school, where the Children's Rondalla of the Colegio México (Rondalla Infantil del Colegio México) and the Estudiantina of the Miguel Ángel Institute (Estudiantina del Instituto Miguel Ángel) would sing three songs for the Pope; two of those songs would be Tú eres Pedro (a hymn composed by Alejandro Mejía) and Himno a la alegría, but the organizers couldn't decide on the third song.
[7] This helped Roberto Carlos' original version to find commercial success once more and to return to the Mexican charts, eventually reaching #1 once again for two weeks beginning on 30 March 1979, a little over a year since it had first done so.
[8] The event was recreated in the 1980 movie "Amigo", starring child actor and singer Pedro Fernández, where at the end of the film Fernández' character is shown as being part of the children's choir who sang Amigo for Pope John Paul II; the movie shots are intertwined with actual footage from the Pope's visit to the Basilica of Our Lady of Guadalupe.
In 2004, American singer Marc Anthony covered "Amigo" on his studio albums, Amar Sin Mentiras (2004) and Valió la Pena (2004) as a ballad and salsa version, respectively.