About an hour into Amandla, a new documentary on the role that song played in the battle against apartheid in South Africa, South African Parliament member Thandi Modise appears onscreen to recount her experiences as a freedom fighter.

Modise, who was arrested as a teenager and spent the second half of the 1970s in prison, does not begin her testimony with stories of military triumphs or interrogation and torture.

Instead, she remembers what any woman would remember from when she was 19: her first love.

“Thandi’s story is one of my favorites because it’s so unexpected,” says director Lee Hirsch.

Amandla: A Revolution in Four Part Harmony opens next Friday at the Harvard Square Loews theater.

The film begins with the singing of children who watch the exhumation and reburial of their executed father’s corpse.

Closing with the sight of newly-elected president Nelson Mandela gleefully dancing amid throngs of followers, Amandla constantly reaffirms the humanity and emotion of both its Afrikaaner and black South African subjects.

The movie tells the story of black South African freedom music and how it articulated and embodied the people’s spirit during the struggle to end apartheid.

In 1948, the all-white National Party came to power in South Africa, and apartheid began. The next forty years were a whirlwind of riots, insurrections, arrests and massacres, with black South Africans the greatest victims of the violence.

“Amandla,” the Xhosa word for “power,” was the rallying cry that activists used to punctuate the end of many songs.

The songs’ actual content changed over the years, reflecting the shifting political climate in the country.

In the 1950s, the African National Congress (ANC) organized a massive non-violent campaign against apartheid. Songs like “Nkosi Sikelel’i,” the People’s Anthem, a prayer for peace and harmony, accompanied the rallies.

But as the struggle turned more violent, so did the songs.

In the 1980s the music was combined with a sort of high stepping dance, known as toyi-toyi to both the police and the participants.

Toyi-toyi became a valuable tool, both as an effective way to physically condition members of the underground and an intimidation technique against the police.