"Ultraviolet" and "The Ballad of Paul K" are two songs by British pop rock band McFly. They were released as a double A-side single on 12 December 2005, serving as the fourth single from the band's second studio album, Wonderland (2005). The single peaked at 9 on the UK Singles Chart (their first not to reach the top five) and No. 25 on the Irish Singles Chart
Both tracks were written by McFly members Tom Fletcher and Danny Jones, with "The Ballad of Paul K" being written also by Dougie Poynter, who was the principal writer. The Ballad of Paul K was based on the members of McFly's fathers. The song is about a middle-aged man coming to terms with his life. The song "Ultraviolet" was initially called "Summer Girls".
The "Ultraviolet" video was simply a montage of clips filmed at Live at McFly's Wonderland Tour 2005, Manchester and Behind the Scenes of their first Arena tour. The Ballad of Paul K video was a little different. The video uses a blend of live action and animation. It is often considered to be in the style of Tim Burton movies, especially The Nightmare Before Christmas and Corpse Bride. In a TV interview, McFly admitted that watching the video now does scare them slightly.