Panic! at the Disco is an American rock band from Las Vegas, Nevada, formed in 2004. Since its inception, the band's line-up has included Brendon Urie and Spencer Smith, and as of 2010, bass guitarist Dallon Weekes.
Founded by childhood friends, Ryan Ross, Spencer Smith, Brent Wilson and Brendon Urie, Panic! at the Disco recorded its first demos while its members were all in high school. Shortly after, the band recorded and released its debut studio album, A Fever You Can't Sweat Out. Made known by the top ten lead single, "I Write Sins Not Tragedies", the album eventually was certified double platinum in the US. In 2006, founding bassist Brent Wilson was fired from the band during an extensive world tour, and subsequently replaced by Jon Walker.
Influenced by 1960s rock bands, The Beatles, The Zombies and The Beach Boys, and preceded by the hit single, "Nine in the Afternoon", the band's second studio album, Pretty. Odd., marked a significant departure from the sound of the band's debut, and ultimately led to the departure of guitarist and principal songwriter Ryan Ross and bassist Jon Walker, who favored the band's new direction. The duo subsequently formed a new band, The Young Veins, leaving Brendon Urie and Spencer Smith as the sole remaining members of the band.