The band consists of Jack Antonoff (of Steel Train), Andrew Dost (of Anathallo), and Nate Ruess (of the Format).

[6] Fun formed in 2008, and their debut studio album, Aim and Ignite, was released in 2009 to moderate commercial success.

It spawned their biggest hit singles to date: "We Are Young" featuring Janelle Monáe, "Some Nights" and "Carry On", all of which reached the top 20 on the U.S.

Immediately afterwards, Nate Ruess asked Andrew Dost and Jack Antonoff to join his new project.

[13] AllMusic called the album "progressive, but in the best possible way" and admired Ruess's lyrics for "investigating the larger truths of life...with a witty approach that keeps the songs bubbling merrily along on a positive note".

She praised songs "Be Calm" and "The Gambler", but criticized the lyrics and production of the album's early tracks.

Hung concluded that while Aim and Ignite is "pretty original to say the least", it "fails to live up to the Format's last outing.

Shane applauded the album's songwriting and said "many of the songs are really good," but he objected to the "cute" production, desiring to hear the band "in a more stripped-down form."

I think much of their recorded work is too fussed over, but when I saw them live and their sound was more stripped down out of necessity, emphasizing their powerful songwriting, I thought they were wonderful.

[23] To celebrate the Paramore U.K. tour and the band's new single "Walking the Dog", Hassle Records gave away a free download of an acoustic version of the track.

Its first single, called "We Are Young" featuring Janelle Monáe, has since been used in several other media, including television series Gossip Girl,[25] 90210,[26] Glee, and Chuck;[27] commercials for Chevrolet[28] and Apple;[29] and in the trailer for Judd Apatow's film This Is 40.

[30] On December 12, 2011, the band's song "One Foot" was available for instant streaming and free download on Nylon's website.

[31] On February 13, 2012, the band released an album stream of Some Nights on their website along with a note from Ruess thanking fans for their ongoing support.

Entertainment Weekly predicted that "We Are Young" would bring home the Grammy in the categories Record of the Year and Song of the Year (writing, of the latter, "'We Are Young' is the kind of anthem this category is made for"), and that Some Nights would win for Best Pop Vocal Album.

[43] On June 18, 2014, Fun performed the song "Harsh Light" on The Tonight Show Starring Jimmy Fallon.

On February 4, 2015, the band announced on its Facebook page and their official website that they were not splitting up, but were taking some time off to pursue other projects.