Euro metal pioneers OZ were formed in Nakilla, Finland, in 1977. The original incarnation of the band consisted of Tapani Hämäläinen (Ape DeMartine) on vocals, Kari ELO on guitar, Tauno Vajavaara (Tani) on bass and Pekka Mark (Mark Ruffneck) behind the drums. After playing up and down Finland, OZ moved to Stockholm in 1983 and signed a long-term deal with Börje Forsberg's Tyfon Grammofon AB label. They went on to become one of the most important heavy metal bands in Scandinavia recording five studio albums all in all before splitting up in the winter of 1991/92. Originally Released in 1986, Decibel Storm was the bands fourth album It followed OZ (1982), the band's landmark album Fire In The Brain (1983) and III Warning (1984).