The massive Hong Kong protests against the government’s proposed extradition bill have had no shortage of extraordinary moments, as more than a quarter of the city’s population of 7 million have stood courageously against China’s creeping authoritarianism. For South Korean observers, however, one particular moment stood out. During the height of the demonstrations, on June 14, a protester with a guitar took the stage at the downtown Chater Garden and sang “March for the Beloved,” an iconic protest song of South Korea—first in Chinese, then in Korean. The protester introduced it as “the anthem for the May 18 Gwangju Democratization Movement” and “the song sung by a million Koreans in 2017 as they protested against [former president] Park Geun-hye.”

The global success of K-pop is a well-known story. Far less well known, even among most Koreans, is the story of how South Korea’s protest music has traveled internationally. From the postwar division of the Korean Peninsula until democratization in 1987, South Korea had a succession of authoritarian rulers. Protest music has been an integral part of the country’s long march toward democracy, and today it serves as an inspiration for freedom throughout Asia.

Korea’s tradition of protest music is traceable to the early 20th century. The Independence Army—the guerrilla fighters who resisted Imperial Japan’s long occupation—had its own set of military marching songs, carrying a message of defiance against colonialism. But it was not until the late 1970s that protest music became a separate genre. Until that point, Korea’s democracy activists and labor unionists had borrowed general pop numbers that carried messages of resistance and empowerment. Also popular were US folk songs such as Bob Dylan’s “Blowin’ in the Wind” and Christian hymns associated with the civil rights movement such as “We Shall Overcome.”

This tradition has continued to this day, incorporating newer songs to create a broad and diversified repertoire. In the 2016–17 candlelight protests, during which more than a million South Koreans gathered every week for 17 weeks to demand then-President Park’s resignation or impeachment, the protest music included Girls’ Generation’s “Into the New World” and the soundtrack for the TV drama Secret Garden (reportedly Park’s favorite show).

The greater degree of labor organization in the mid-to-late 1970s, and the subsequent crackdown by the dictatorship, drove the activists to create their own group identity, set apart from the wider Korean society. Music was a crucial medium in creating this newly shared identity. Musicians who were involved in the democracy movement began to compose what came to be known as “the people’s music” for the specific purpose of inspiring activists and the public. Particularly important was the influence of Christian organizations, which stood at the forefront of the country’s social justice movements and labor organizations. Songs for Tomorrow, the first modern anthology of protest music, was published in 1975 by Christian Academy, a Presbyterian social justice ministry. Much of the significant protest music came to bear explicitly Christian themes, such as Kim Min-gi’s “Jesus of Golden Crown.”

The Gwangju Uprising in 1980 was a major turning point in South Korea’s struggle for democracy. Dictator Chun Doo-hwan sent paratroopers to attack peacefully protesting citizens in the southwestern city of Gwangju. They killed hundreds and injured thousands, in one of the deadliest massacres in modern South Korean history. This traumatic moment gave rise to numerous protest songs, one of which was “March for the Beloved,” which attained an iconic position in South Korea’s political culture. Composed by Kim Jong-ryul, who was a student at Chonnam National University, which stood in the center of the uprising, “March for the Beloved” was the closing number for a 1981 musical that commemorated the massacre. Composed in the style of a military march set in a minor key, it conveys a sense of grim determination. The song’s famous refrain, “As we have gone first / follow us, the living,” suggests a call of sacrifice from beyond.

As Gwangju’s memory galvanized South Korea’s democracy movement, “March for the Beloved” quickly spread throughout the country as a way to remember the fallen, and eventually became the unofficial anthem of the June struggle of 1987, which finally ended authoritarian rule. In 1997, a democratized South Korea designated May 18 as the day of remembrance for the Gwangju Uprising, and the official ceremony includes a rendition of the song.

Even more remarkable, however, is how “March for the Beloved” spread across Asia, where it was sung at major protests to inspire solidarity. The Asia-wide exchange among democracy activists, labor unions, and Christian groups facilitated this spread.

Hong Kong was the first international locale that adopted the song. According to a 2016 study by Professor Jung Keun-sik of Seoul National University, activist Angela Wong, who is now a professor at the Chinese University of Hong Kong, first heard it in 1982 as she was visiting Korea as a delegate of Hong Kong’s Christian student association. In an exchange program held with the Korea Student Christian Federation, which was then at the forefront of Korea’s democratization movement, Wong noted that the Korean youth repeatedly sang “March for the Beloved.” Inspired by the music, Wong translated the lyrics and sang the song with her compatriots after she returned to Hong Kong in 1984.

The song spread to other Asian countries through similar paths. Jung’s study notes that it reached Taiwan through an exchange program involving labor leaders from South Korea and Taiwan and was widely sung in Taiwan by 1989. From the Hong Kong version, labor activists outside of Beijing adopted their own based on the same melodies, calling it “The Hymn of Laborers.” Cambodia, Malaysia, Thailand, and Indonesia are also known to have their own versions of the song, adapted to fit the context of their particular struggles for freedom.

The playing of “March for the Beloved” before the million-plus protesters in Hong Kong inspired a strong response from South Korea, eliciting rare bipartisanship in Korea’s National Assembly in support of the protests. The song thus achieved the precise goal for which it was created: to inspire solidarity among freedom-loving people.