Nirvana were part of a rock music genre from Seattle called grunge. The genre comes from both punk rock and heavy metal. They released their first album, called "Bleach", for record label Sub Pop in 1989. Nirvana's style was songs with quiet verses and loud choruses. After signing to record label DGC Records, in 1991, Nirvana became very popular after releasing the song "Smells Like Teen Spirit". This song was the first single from their second album "Nevermind" (1991), which sold over 30 million copies worldwide. Nirvana becoming popular also made alternative rock popular. Cobain was then called by some people the "spokesman of a generation".