"Till the World Ends" is a song recorded by American singer Britney Spears for her seventh studio album, Femme Fatale (2011). It was written by Lukasz "Dr. Luke" Gottwald, Alexander Kronlund, Max Martin and Kesha Sebert. Gottwald, Martin and Billboard produced the song, while vocal production was handled by Emily Wright. "Till the World Ends" is composed as an uptempo dance-pop and electropop song with an electro beat. It opens with sirens, and has elements of trance and Eurodance. The song features a chant-like chorus, and lyrics in which Spears sings about dancing until the end of the world. "Till the World Ends" received comparisons to past hits by artists such as Kesha and Enrique Iglesias. The song received universal critical acclaim, with critics calling it a catchy dance track and complimenting its anthemic nature.