Premise: Kurt Donald Cobain (February 20, 1967 – April 5, 1994) was an American musician, artist, singer, songwriter, guitarist and poet. Born in Aberdeen, Washington, Cobain formed the band Nirvana with Krist Novoselic in 1987 and established it as part of the Seattle music scene and grunge genre. Nirvana's debut album "Bleach" was released on the independent record label Sub Pop in 1989.
Hypothesis: Cobain formed Nirvana when he was twenty years old