The Santiago Times reported Jara was targeted, tortured and killed during the 1973 coup that brought Gen. Augusto Pinochet's dictatorship to power.
"This isn't a moment for celebration; it is a moment to be calm and recognize we have much work ahead in order to achieve true justice, especially true justice for all the victims who suffered too much in this place and many other places in Chile," Jara's wife, Joan, said.
The eight men were arrested Dec. 28.
The Times said Pinochet was responsible for 3,000 deaths and more than 30,000 torture cases.
Jara was held as a prisoner after Pinochet's forces raided the university where he was a professor. He was also a folk singer. His body was found days later with evidence of torture and 44 bullet wounds.
Judge Miguel Vasquez charged two former military officers, Hugo Sanchez and Pedro Barrientos, and named six others, Roberto Souper, Raul Jofre, Edwin Dimter, Nelson Hasse, Luis Bethke and Jorge Smith, as accomplices.