By August 23, 2003, when Red Hot Chili Peppers performed at Slane Castle, they were enjoying significant commercial success following the release of their eighth studio album, "By the Way," which came out in July 2002. This album marked a period of renewed creativity and was a departure from the band’s earlier work, with more melodic elements and a focus on introspective lyrics. While "Can't Stop," one of their signature songs, features prominently in the setlist from this live performance, it was already a well-established hit, having been released as the lead single from "By the Way." The concert showcased the band's energetic live performance style and demonstrated their ability to entertain massive audiences. Moreover, the Slane Castle event was part of a series of high-profile shows that further solidified the Chili Peppers' status as one of the top rock bands of their era.