It's what we're living in basically, the world in a state of night." "The whole album kind of tells the story of the night - staying up during the night - but it's also an allegory. "Gorillaz make dark pop that's what they always set out to achieve," Albarn said in an interview with MTV News. And that will happen to us in our lifetime." And then you wake up in the morning with this nightmare in your head and it's blue sky and beautiful sand, which looks fantastic now but was probably something else millions of years ago. There are little satellite towns in the middle of these semi deserts that are absolutely on their knees. "Dust bowls, loose earth rapidly turning into desert. It was basically dead trees as far as the eye can see," Albarn recalls. Despite this, the album's main source of inspiration actually came about as a result of Albarn's train journey from Beijing to Mongolia where he, his partner and six-year-old daughter spent a day travelling through what Albarn describes as a "weird, unspoken, forgotten part of China. By the time Albarn was ready to start writing and recording material for the Gorillaz movie, the whole idea had already been scrapped, although ideas from the movie's script were still used, including the themes of being driven by ego and the world being trapped in an endless night. While Jamie Hewlett was working with his team on a script for a possible Gorillaz movie, Damon Albarn was still recording Think Tank with Blur. Complex included it on their list of 100 Best Albums of the Complex Decade, placing it at number 43, and Spin later included it in their list of "The 300 Best Albums of 1985–2014". The NME placed the album at number 98 on their list of 100 greatest albums of the decade, and Uncut placed it at number 75 on their list of top 150 albums of the decade. Spin ranked Demon Days as the fourth-best album of 2005, while Mojo ranked it at number eighteen on their year-end list and hailed the album as a "genre-busting, contemporary pop milestone". The album spawned the singles " Feel Good Inc.", " Dare", " Dirty Harry", " Kids with Guns", and " El Mañana".
Outperforming their debut, the album has sold eight million copies worldwide. The album reached number one on the UK Albums Chart and number 6 on the US Billboard 200, and was later certified six times platinum in the UK and double platinum in the US. Upon its release, Demon Days was a chart success reaching the top 10 in 22 countries.
Almost all visuals associated with the album were designed by Gorillaz co-creator Jamie Hewlett, under his design company Zombie Flesh Eaters. As with the band's eponymous 2001 debut, the release of Demon Days and its respective live performances were both accompanied by various multimedia, including interactive features on the Gorillaz website, a total of four animated music videos, and animatics for select videos.
Produced by the band, Danger Mouse, Jason Cox, and James Dring, the album features contributions from De La Soul, Neneh Cherry, Martina Topley-Bird, Roots Manuva, MF Doom, Ike Turner, Bootie Brown of the Pharcyde, Shaun Ryder, and Dennis Hopper. It was first released on in Japan and on in the United Kingdom by Parlophone and in the United States by Virgin Records. Demon Days is the second studio album by British virtual band Gorillaz.