Viper is a Brazilian heavy metal band formed in 1985, when brothers Pit (bass) and Ives Passarell (lead guitar) joined up with guitarist Felipe Marchado, drummer Cassio Audi and singer Andre Matos. After a few demos, Viper's first album, Soldiers of Sunrise, was released in July 1987; it was a fairly raw-sounding Iron Maiden-type album and was very successful in Brazil. After Sergio Facci took over on drums, Viper returned to the studio and recorded Theatre of Fate in 1989.

This second album featured much more mature songwriting, heavily influenced by classical music. This, combined with Andre Matos' greatly improved singing, made Theatre of Fate a top-notch progressive metal album. While Matos wanted Viper to continue in this neo-classical, progressive metal style, the rest of the band wanted to move back to a more standard metal sound. This resulted in Matos leaving the band to form Angra. Matos was not replaced by a new member; Pit Passarell became the new singer, while Renato Graccia became the new drummer.

Evolution was released in 1992, trading classical influences and the operatic singing of Andre Matos in favor of a straight hard rock style. 1994's Coma Rage found Viper going in yet another direction. This album has a raw, heavy punk rock sound, showing that Viper likes to keep changing its sound and never makes the same album twice. ~ David White, All Music Guide