Indexi formed in 1962, and their name was derived from the Index which was a students' grade log. They began by making instrumental covers of popular hits, but in 1967 started composing. They were known as the Pioneers of Psychedelic Rock, and were inspired by many bands like the Beatles and Yes.Some of their most notable songs are Plima, Sve ove godine, Svijet u kome živim, Sanjam and Bacila je sve niz rijeku, which was later covered by many other ex-Yugoslavian groups.