While Kim Jong Un apparently clapped and cheered at the performance of young K-pop acts last year, his subjects are forbidden from listening to the music. Photo / AP
As a girl, Ryu Hee-Jin was brought up to perform patriotic songs praising the iron will, courage and compassion of North Korea's leader at the time, Kim Jong Il.
Then she heard American and South Korean pop music.
"When you listen to North Korean music, you have no emotions," she said. "But when you listen to American or South Korean music, it literally gives you the chills. The lyrics are so fresh, so relatable. When kids listen to this music, their facial expressions just change."
Western music once helped tear a hole in the Iron Curtain — Soviet youths listened to illicit recordings of the Beatles, and in 1987, young East Berliners gathered near the Wall to hear David Bowie's emotional performance of Heroes in the divided city's west side.
Now, there is evidence that South Korean K-pop is playing a similar role in subtly undermining the propaganda of the North Korean regime, with rising numbers of defectors citing music as one factor in their disillusionment with their government, according to Lee Kwang-Baek, president of South Korea's Unification Media Group (UMG).
The trend, fuelled by growing cellphone ownership in North Korea and the country's still buoyant border trade with China, has provoked a new clampdown by Pyongyang in the past year, according to reports on Daily NK, a defector-led news service with extensive links in the North. That followed Kim Jong Un's 2018 vow to "crush bourgeois reactionary culture."
A survey of 200 recent defectors by UMG released in June found that more than 90 per cent had watched foreign movies, TV and music in North Korea; three-quarters knew of someone who had been punished as a result; and more than 70 per cent said it had become more dangerous to access foreign media since Kim Jong Un took power at the end of 2011.
Ryu is one of many defectors who say K-pop and Western popular music opened their eyes, convincing them that North Korea was not the paradise it was made out to be and that their best prospects lay abroad.
In her bedroom in Pyongyang, the North Korean capital, Ryu would sometimes stay up all night watching a single music video on repeat — surreptitiously, for fear of the police.
"We were always taught that Americans were wolves and South Koreans were their puppets," she said, "but when you listen to their art, you've just got to acknowledge them."
She remembers Celine Dion, the British violinist "with the crazy hair" Nigel Kennedy and the Irish boy band Westlife, as well as K-pop bands TVXQ, Girls' Generation and T-Ara.
Born into a musical family, Ryu played the gayageum, a traditional Korean string instrument similar to a zither, at an arts school in Pyongyang.
A spell in the national synchronized swimming team was followed by a job as a waitress in southern Europe.
There, she spent evenings in nightclubs, dancing "Gangnam Style" with co-workers and friends from South Korea. In 2015, at 23, she defected to the South.
Former defectors based in South Korea have long understood the power of foreign news and culture in countering the regime's propaganda.
Projects such as Flash Drives for Freedom smuggle in USB sticks loaded with Hollywood movies and American television shows, as well South Korean dramas and music videos.
Voice of America, Radio Free Asia, the BBC World Service and defector-run stations broadcast Korean-language radio programming into the North — mainly news, but also music.
But growing private enterprise may be the most powerful driver of change, with videos brought in en masse by traders who cross back and forth from China.
The risks for viewers are real, with a special unit of the police and security services known as Group 109 in charge of the renewed crackdown. Even minors who are caught can face six months to a year of ideological training in a reeducation camp — unless their parents can bribe their way out — while adults can face a lifetime of hard labour or, for sensitive material, even execution.
It's not just the melodies and lyrics that prove catchy, it's also the performers' clothes and hairstyles.
"The kind of thing I wanted to do was dye my hair and wear miniskirts and jeans," said Kang Na-ra, 22.
"Once I wore jeans to the market, and I was told I had to take them off. They were burned in front of my eyes."
Kang, who had been a singer at an arts high school in Pyongyang, defected in 2014, so "I could express myself freely."
She tried to make it in K-pop but says the singing styles are too different.
Now she has a successful career as a TV personality and an actress, mainly portraying North Koreans in South Korean films and dramas.
Han Song-ee was just 10 when she first saw a video of Baby V. O. X playing in a "Unification Concert"in Pyongyang in 2003, to an audience of comically impassive North Korean bigwigs.
"At first it was so shocking and weird to see these 'capitalist vandals,' but as I listened to their music, I realized it was pretty catchy," she said.
Soon, she was hooked. Her father became angry with her mother for copying the band's hairstyle.
Later, Han and her friends began to wear the colourful hot pants popularised by South Korea's Girls' Generation — but only in their neighbourhood, not the city centre.
Han defected in 2013 and is now a well-known vlogger in Seoul, where she also appears on radio and television. She says she dreams of North Koreans being able to watch her broadcasts, and of her parents tuning in, "so they can see how free I am."
North Korea's leaders have shown contradictory impulses when it comes to the South, pushing a narrative of Korean unification, even as they discourage cultural crosscurrents at home.
Last year, Kim attended a South Korean musical performance in Pyongyang that included older music divas, male rock musicians and young K-pop acts, including a trendy girl band called Red Velvet.
The concert was broadcast in its entirety in the South, but only in snippets on news programmes in the North.
One woman in her late 20s, who escaped North Korea last year, said video of the concert was shared behind closed doors in her hometown near the Chinese border.
She spoke on the condition of anonymity because of safety concerns.
"Kim Jong Un apparently clapped and cheered at the performance, but we could only watch smuggled footage of it in hiding because consuming South Korean music was still a crime that could land us in prison," she said.
After she defected, Ryu said, she learned from a TV documentary that Kim Jong Il, the father of the country's current leader, was a fan of South Korean cinema and TV shows.
"I was so, so angry," she said. "We would literally cry when we sang about the hardships of Kim Jong Il's life. I never imagined he was watching South Korean TV."
These days, Ryu is studying for a business degree but still dreams of breaking into K-pop or — better yet — Hollywood.
"It's so incredible how far I have come," she said. "South Korean music really played a central role in guiding me through this journey."