Mylo Xyloto was Coldplay's fifth studio album and was originally released in 2011, with Brian Eno as one of the producers. The album was conceived as a concept album, telling a love story set in a dystopian city. Musically, the band opted for a colourful, electronically tinged pop sound. Every Teardrop Is a Waterfall, Paradise and Charlie Brown were among the album's best-known songs. Princess of China was a duet with Rihanna. Mylo Xyloto reached number 1 on both the UK Albums Chart and the US Billboard 200.