A video in which six judges used rap to encourage the use of electronic evidence in civil cases, one of many efforts to promote China's Constitution, went viral online on Wednesday.

In the video named The Rap of the Court, the six judges, who all work at the Jiang'an District Court of Wuhan, Hubei province, promote the right ways to collect and save nine types of electronic materials as evidence, which include Alipay, WeChat, online conversation records, recordings and text.

"These people (the six judges) who are familiar with court affairs polish each sentence of the rap to make the content professional and easily understood," said Tan Juan, the director of the rap, who also works at the publicity and education office of the court.

It took the judges more than two months to complete the content of the rap, leaving only one week for them to practice, said Tan.

"I felt it was more challenging to shoot the rap video than deal with a big court case," said Liu Bingjing, who is around 30 years old, adding this is totally different from her work style as a judge.

"We hope to promote the Constitution in brand new and down-to-earth ways to make the laws easier to understand. Meanwhile, with this video, we want to show complete images of our judges -- they are strict and low-profile at work, but in life, they are like ordinary people, who know fashion, love music and can play it cool," said Tan.