Queen are a British rock band that formed in London in 1970. Their classic line-up was Freddie Mercury (lead vocals, piano), Brian May (lead guitar, vocals), Roger Taylor (drums, vocals), and John Deacon (bass guitar). Queen's earliest works were influenced by progressive rock, hard rock and heavy metal, but the band gradually ventured into more conventional and radio-friendly works by incorporating further styles, such as arena rock and pop rock, into their music.

At the end of 2004, May and Taylor announced that they would reunite and return to touring in 2005 with Paul Rodgers (founder and former lead singer of Free and Bad Company). Brian May's website also stated that Rodgers would be "featured with" Queen as "Queen + Paul Rodgers", not replacing Mercury. The retired John Deacon would not be participating. In November 2004, Queen were among the inaugural inductees into the UK Music Hall of Fame, and the award ceremony was the first event at which Rodgers joined May and Taylor as vocalist.  Between 2005 and 2006, Queen + Paul Rodgers embarked on a world tour, which was the first time Queen toured since their last tour with Freddie Mercury in 1986. The band's drummer Roger Taylor commented; "We never thought we would tour again, Paul [Rodgers] came along by chance and we seemed to have a chemistry. Paul is just such a great singer. He's not trying to be Freddie." The first leg was in Europe, the second in Japan, and the third in the US in 2006. Queen received the inaugural VH1 Rock Honors at the Mandalay Bay Events Center in Las Vegas, Nevada, on 25 May 2006. The Foo Fighters paid homage to the band in performing "Tie Your Mother Down" to open the ceremony before being joined on stage by May, Taylor, and Paul Rodgers, who played a selection of Queen hits.  On 15 August 2006, Brian May confirmed through his website and fan club that Queen + Paul Rodgers would begin producing their first studio album beginning in October, to be recorded at a "secret location". Queen + Paul Rodgers performed at the Nelson Mandela 90th Birthday Tribute held in Hyde Park, London on 27 June 2008, to commemorate Mandela's ninetieth birthday, and again promote awareness of the HIV/AIDS pandemic. The first Queen + Paul Rodgers album, titled The Cosmos Rocks, was released in Europe on 12 September 2008 and in the United States on 28 October 2008. Following the release of the album, the band again went on a tour through Europe, opening on Kharkiv's Freedom Square in front of 350,000 Ukrainian fans. The Kharkiv concert was later released on DVD. The tour then moved to Russia, and the band performed two sold-out shows at the Moscow Arena. Having completed the first leg of its extensive European tour, which saw the band play 15 sold-out dates across nine countries, the UK leg of the tour sold out within 90 minutes of going on sale and included three London dates, the first of which was The O2 on 13 October. The last leg of the tour took place in South America, and included a sold-out concert at the Estadio Jose Amalfitani, Buenos Aires.  Queen and Paul Rodgers officially split up without animosity on 12 May 2009. Rodgers stated: "My arrangement with [Queen] was similar to my arrangement with Jimmy [Page] in The Firm in that it was never meant to be a permanent arrangement". Rodgers did not rule out the possibility of working with Queen again. Answer this question using a quote from the following article:

what happened in 2004
At the end of 2004, May and Taylor announced that they would reunite and return to touring in 2005 with Paul Rodgers