Watching John Pirozzi’s documentary Don’t Think I’ve Forgotten: Cambodia’s Lost Rock and Roll is both a joyful and unsettling experience. In the space of two hours the film lets you fall in love with the vibrant and talented characters of Cambodia’s 1960s and 1970s music scene and then relates how almost all of them were killed.

Splicing together contemporary interviews with films from the period, archival footage, home movies, old newsreels, photos and cleverly animated record covers, Don’t Think I’ve Forgotten spans the period from Cambodian independence in 1953 to 1979, when the Khmer Rouge were driven out of Phnom Penh.

A co-production between Pirozzi and the Documentation Center of Cambodia, the film had its world premiere on Saturday night at Phnom Penh’s historic Chatomuk Theatre. The packed invite-only screening was followed by a question-and-answer session with the filmmaker and some of those interviewed in the film, and then a concert outside featuring some of the surviving musicians and Dengue Fever singer Chhom Nimol.

Filmmakers conducted more than 70 interviews across Cambodia, the United States, France and Singapore, although only a fraction of them ended up being used. Highlighted in the film is a selection of the more influential figures like crooner and songsmith Sinn Sisamouth, the golden voice Ros Serey Sothea, cheeky and rebellious Yol Aularong and the members of the guitar bands Drakkar and Baksei Chamkrong. In the years the regime was in power, records were destroyed and singers murdered.

At a basic level, the film serves as a digestible primer on a period of Cambodian history, touching on the major figures and events that precipitated Pol Pot’s takeover and delivering the full horror of the mass murderer’s reign. Prince Norodom Sirivudh and historian David Chandler provide historical context and narrative while musicians give first person insights into the effects the war that lead up to the Khmer Rouge takeover and the horror of living in Pol Pot’s “agrarian utopia”.

The newly discovered footage of Phnom Penh alone makes the film worth watching: from the clean and modern-looking city of the 1950s to the overgrown streets left deserted after the Khmer Rouge. Shots of life in the street from the 1960s and 1970s – cyclos gathering outside the National Radio Station to listen to Sisamouth’s songs, people shopping at the Central Market – provide a rare glimpse into the vibrant and hopeful community torn apart by outside forces and ultimately wasted by the Khmer Rouge.

But it’s the musicians who are at the heart of the film. Among the survivors interviewed was the bashful Mol Kagnol – lead guitarist for Baksei Chamkrong, Cambodia’s very first guitar band – who talks about watching his brother and lead singer Mol Kamach get all the girls while Kagnol was followed around by the guitar nerds.

Then there are the interviews with the families of those musicians who didn’t survive, including Sinn Sisasmouth’s son, who never found out the true circumstances of his father’s death. Two of Ros Sereysothea’s sisters remember how she was called the “little cicada” because she would never stop chirping as a child.

One of the most engaging interviewees is Thida Mam, the mother of Cambodian-American singer Laura Mam, who provides a fan’s perspective on the scene. She idolised the likes of Sereysothea and the free-spirited singer Pan Ron and later bonded with other city folk toiling in the fields by singing pop songs when out of earshot of Khmer Rouge cadre.

Hopeful images like these are scatted through the film which, despite the tragic subject matter, doesn’t dwell on sadness. It was fitting, then, that the mood in the theatre after Saturday night’s screening was an ebullient one – a happy reflection of its endearing, enduring stars.