Alternative rock emerged in the 1980s as a genre involving guitars, drums, bass, and vocals without synthesisers. It grew popular in the 1990s with bands like Nirvana and R.E.M. Nirvana's 1991 album "Nevermind" featuring the hit "Smells Like Teen Spirit" exposed alternative rock to mainstream audiences. While originally underground, the genre saw increasing popularity throughout the 1980s and 1990s before some decline in the 2000s, though remains an influential genre today.