Subtitled “Cambodia’s Lost Rock and Roll,” this documentary charts the country’s pop music industry from the 1950s to the late ’70s vis a vis the surrounding political climate. The explosion of rock ‘n’ roll in the West happened to coincide with the first years of Cambodia’s independence from France; as the monarchy embraced Western technology in its campaign to modernize the country, so did the populace fall in love with Western music. Throughout the 1960s, Cambodia would produce not only rock and pop acts, but also groups inspired by soul, psychedelia, and South American dance music. The flourishing music scene would end, of course, with the triumph of the Khmer Rouge, who imprisoned or killed almost all of the nation’s artists. This is eye-opening and frequently moving, elevated by sharp editing that imaginatively juxtaposes major events in government and entertainment history. John Pirozzi directed. In English and subtitled French and Khmer.