Slovenian pop group Prizma was formed in the spring of 1974 by Igor Kos, Vladimir Mljač and Franci Čelhar. The fourth member was bass guitarist Vili Bertok, who left the band in 1976 and joined Buldožer. He was replaced by Danilo Kocjančič. In 1984 Danilo Kocjančič left the band and joined Bazar and Dušan Šandrič joined in. This lineup last until October 1987, when the band friendly split.