Kaaos was a Finnish hardcore punk band from Tampere, Finland. Formed in March 1980, they were one of the first hardcore punk bands in Finland to release a record (the first being Rattus, at a time an ordinary -77 style punk band), and though their lineup has changed frequently through the years, the band is somewhat active through the years. Only the band's guitarist Jakke (who later became the vocalist) remained as the original member and grew to become the center figure of Kaaos. Jakke Hallikainen died on 29 November 2007. He died of alcohol-related causes at the age of 42.