Cassius is a French musical duo. In 1991, they created their first project, called La Funk Mob, and the following year, they started to increasingly experiment with electronic sounds. They collaborated with Wu-Tang Clan members and Jocelyn Brown and worked together on the soundtrack of a DC Comics movie. While rehearsing their 15 Again album tour, Cassius provided the community with the a cappella track of their single "Toop Toop" and encouraged fans and friends to start remixing the song. It became an immediate success: the band started the Cassius Workshop project and released more a cappellas for remixing purposes. They claim to have received more than 400 remixes. Cassius's song "I Love You So" was sampled on the track "Why I Love You" on Jay-Z and Kanye West's 2011 collaboration album Watch the Throne.