Nirvana was an influential grunge band known for its raw sound and anti-establishment ideology. The band incorporated elements of punk rock and heavy metal into its music through distorted guitars, screaming vocals, and simple song structures. Nirvana helped popularize grunge music in the early 1990s with the release of its breakthrough album Nevermind. Featuring the hit single "Smells Like Teen Spirit", Nevermind topped music charts worldwide and has sold over 30 million copies, making it one of the best-selling albums of all time.