He wrote and produced the song "Lay Me Down" with Cyndi Lauper for her 2008 album Bring Ya to the Brink. An instrumental version of the song appears on Kleerup's album under the title "Thank You for Nothing". The title was believed to be inspired by Kleerup's anger with Cyndi Lauper for not allowing her version to appear on his album, but this was later confirmed as a false rumor in an interview. Turns out the song was originally made before he gave it to Cyndi Lauper, and he decided to use the original version on his album instead.
His song, "Until We Bleed" featuring Lykke Li, was featured in the British television show, Misfits.