In September 2001, during the performance at Slane Castle, U2 was riding the wave of success from their album "All That You Can’t Leave Behind," which had been released the previous year. This album marked a significant comeback for the band, showcasing a return to their classic sound while incorporating more melodic and uplifting themes. "Beautiful Day," the lead single, became an anthem of hope and resilience, resonating deeply with fans globally. Notably, the band's return to Slane, a site of historical significance for them, highlighted their strong connection to their Irish roots. The performance was also integral in solidifying the album's success, as U2 embraced a festival atmosphere with a massive crowd, reinforcing their status as a premier live act.