One

When U2 arrived in Berlin in October 1990, just before German reunification, they were seeking inspiration for their new album, Achtung Baby. However, the recording sessions at Hansa Studios became tense. Conflict among the members over musical direction and song quality nearly led the band to split. It was amidst this crisis that "One" emerged. The creative spark ignited when guitarist The Edge was improvising a chord progression. At the suggestion of producer Daniel Lanois, The Edge combined two distinct musical ideas, and the band felt a powerful energy in the room. In just fifteen minutes, the song's melody and structure took shape. The lyrics, written by Bono, stemmed from the band's complex internal relationships, German reunification, and a skeptical view of the idea of "unity" without differences. The song became a turning point, reaffirming the group's confidence and marking the start of a new creative chapter.

"One" was released as a charity single, with proceeds going to AIDS research. It reached the top of the charts in Ireland, Canada, and on Billboard's rock categories in the United States. The song has been critically acclaimed and has remained a staple at U2 concerts since its live debut in 1992. Bono has described the song as "about relationships," and its message has transcended, being used to promote human rights and social justice causes. It even lent its name to Bono's charity, the ONE Campaign. The song was later re-recorded in duets, first with Mary J. Blige in 2005 and again for the 2023 album Songs of Surrender. The original recording was completed between October 1990 and September 1991, with contributions from engineers like Paul Thomas and producers like Daniel Lanois and Brian Eno, in studios in Berlin, Dalkey, and Dublin.