"Demon Days" found the band taking a darker tone, partially influenced by a train journey Albarn had taken with his family through impoverished rural China. Albarn described the album as a concept album: "The whole album kind of tells the story of the night — staying up during the night — but it's also an allegory. It's what we're living in basically, the world in a state of night." Believing that the album needed "a slightly different approach" compared to the first album, Albarn enlisted American producer Brian Burton, better known by his stage name Danger Mouse, to produce the album, whom Albarn praised as "one of the best young producers in the world" after hearing his 2004 mashup album "The Grey Album". Burton felt he and Albarn had a high degree of affinity with each other, stating in an interview on the creation of the album: "We never had any arguments. We even have that finish-each-other's-sentences thing happening. There are a lot of the same influences between us, like Ennio Morricone and psychedelic pop-rock, but he has 10 years on me, so I have some catching up to do. Where he can school me on new wave and punk of the late ’70s/early ’80s, I can school him on a lot of hip-hop. We’re very competitive and pushed each other." Similar to the first album, "Demon Days" features collaborations with several different artists, including Bootie Brown, Shaun Ryder, Ike Turner, MF Doom (who was recording with Danger Mouse as Danger Doom at the time) and Martina Topley-Bird, among others.