What is the "secret" before and behind the stage for the 70th anniversary of the founding of the People's Republic of Korea?

September 9th is the National Day of the DPRK and the 70th anniversary of the founding of the DPRK.

Take a look at the military parade in Pyongyang on the morning of September 9.

After the parade, a large group of gymnasts and art performances, "the glorious Motherland" , was subsequently premiered at the Rungrado 1st of May Stadium.

The North Korean travel agency website in Goryeo even described the event as ``the best show on earth" .

What little-known "secrets" are in front and behind the stage, from the participants to the staging of the event?

Who is eligible to participate in the National Day show?

Participating in the National Day celebrations is regarded as an honour by the Korean people, and only the elite of the country is the only one who has the right to play.

In an interview with the BBC, Mr Roh Xichang, a former top official of North Korea's ruling party, was selected for the National Day show and introduced the selection process in an interview with the BBC.

Lu said most of the military parade was attended by elite military units or military academies, while performers were mostly gifted singers, dancers and gymnasts. They all have one thing in common: they are fiercely loyal to their country. Among them were the sons and daughters of North Korean officials.

He noted that during the selection process, staff would conduct a comprehensive survey of the candidates and their families and to critically review the political performance of all their family members, including cousins and cousins. The candidate will not be eligible until it has been verified that there is no adverse record.

However, they are not selected to perform on the National Day, and they will need to be trained.

"performers usually spend months training and rehearsing, day and night, very hard. A lot of people get hurt from high-intensity practice and are forced to quit. In any case, no one ever complains, " Lu said.

What are the highlights of a large group exercise?

The 90-minute mass gymnastic performance has long been considered one of North Korea's most distinctive arts and cultural performances and is the most anticipated performance of the National Day.

Since 1961, North Korea has been creating big group exercises on different themes, such as the time of the workers'party, Qian Lima Korea, follow the banner of the Party, and the people sing praises to the leader.

In 2002, to mark the 90th anniversary of Kim Il-sung's birth and the 60th anniversary of Kim Jong Il's birth, North Korea staged a 100,000-strong "Arirang" , a group exercise and art performance, the performance combines ethnic dance, modern dance, gymnastics, acrobatics and other forms of artistic expression. The performance is also Guinness World Records. Since then, group exercises have become a must-have for North Korea's big events.

According to The Washington Post, the theme of the North's Parade is "the glorious Motherland" , which is named after a patriotic Moranbong Band song, The Washington Post reported. A total of 100,000 North Korean volunteers, including children and children, college students and literary and art workers, took part in the show.

The most striking part of the group exercise is the "artificial background wall" , where thousands of people, under a unified command, display colorful panels with different patterns, such as a jigsaw puzzle that consists of a huge screen, sometimes showing a continuous dynamic picture, it's like an electronic screen.

According to ABC, the show is a rich and colorful scene, with each participant in the "artificial background wall" having a special book with 170 pages in it that they had to listen to and flip over quickly when performing, lift the correct pattern in time.

The performance requires intense teamwork and a high level of concentration, and it doesn't allow for any kind of glitch in the performance. For the perfect performance, the cast trained for eight months.