Nirvana was an influential American grunge rock band formed in 1987 by Kurt Cobain and Krist Novoselic. They released their breakthrough album Nevermind in 1991 featuring the hit single "Smells Like Teen Spirit", which popularized alternative rock. Their third and final studio album In Utero challenged mainstream audiences. The band abruptly ended following Cobain's death by suicide in 1994. Nirvana went on to sell over 25 million albums in the US and over 50 million worldwide, cementing their legacy as one of the most iconic and commercially successful rock bands of the 1990s.