Alta Tensão were one of the best, but sadly also mostly unknown bands in Brazil's '80s heavy metal scene. The band was founded by Bosco Melo (drums) and Edson David (guitar) along with the brothers Adilson Fernandes (vocals/guitar) and Marcos Fernandes (bass) in Sao Paulo, in the year of 1981. They released their first great album, 1985's "Metalmorfose" by one of the then-best local labels, Baratos Afins. After some changes in the band, the Rock Brigade label took over for the second album, 1986's "Portal Do Inferno". That release again contained great heavy metal. After this, the Fernandes brothers would leave, and with a new singer, Bosco continues the band as a 3-piece. The last album recorded with this formation, 1990's "Nigéria", is not so special anymore, where the songwriting changed a lot, but it still had some good songs. They didn't survive the metal crisis in the early-'90s.
(text adapted from sources)