Panic! at the Disco is an American rock duo, formed in Las Vegas, Nevada in 2004. Since its conception, the band's line-up has included Brendon Urie (lead vocals, guitar, piano), and Spencer Smith (drums). Original and former members Ryan Ross (guitar) and Jon Walker (bass) left the group in 2009. The band has been described by critics as a variety of genres, most commonly pop punk, alternative rock, and baroque pop.