With neat ponytails and immaculate grades, the four eight-year-olds who bounded on stage would make any Chinese parent proud -- but wielding electric guitars, these schoolgirls were ready to add another brick in the wall of rock history.

Dressed in blue-sequinned jackets, their band Cool blasted out a song by British pop-rockers McFly in a heavy style echoing 1970s megastars Led Zeppelin, complete with rock star jumps and fist pumps.

"I like to play loud music which annoys old people," said lead singer Zhou Zi, whose favourite toy is a big white teddy bear. "We like rock songs because they're crazy."

Cool's members lead parallel lives as students at a chain of music schools hoping to create a new generation of Chinese rock stars, and the band were one of more than two dozen child outfits battling for honours at a competition in the northern port city of Tianjin earlier this month.

The event -- where bands offered a mix of foreign covers and original tunes -- is a symbol of rock music's move into the mainstream of China's entertainment industry since it met opposition from authorities when it arrived in the country in the 1980s.

A band named Rock Fairytale -- the eventual winners -- played the Guns N' Roses classic "Sweet Child O' Mine" before the 10-year-old leader of another group, dressed in a spangly black shirt and leather boots, gave an impressive rendition of Queen's "We Will Rock You".

Boom, from China's poor Henan province, covered the Beatles' "Twist and Shout".

Asked what he knew about the British foursome, the band's eight-year-old lead singer Jia Tianyi responded: "They're probably from the US."

In defiance of rock cliche, irresponsible backstage behaviour at the competition was limited to impromptu games of hide and seek between band members, while Cool's post-performance routine included eating peaches bought along by the bass player's father.

As well as attending normal classes, the band members also go to the Nine Beats music school in Tianjin, whose founder Li Hongyu says has more than 150 branches across China, and thousands of students in total.

"In the past, if parents wanted to children to study music, they would think of classical musical instruments... but few kids studying classical music are happy," Li said.

"I believe that China's future rock stars can be found at our school," he added. "We are changing the direction of Chinese contemporary music."

China's first homegrown rock acts began to perform in the 1980s when the ruling Communist party relaxed cultural controls -- only to be condemned by officials who shut down concerts and banned some songs from broadcast.

The student protestors in Tiananmen Square repeatedly sang "Nothing to my name" by Cui Jian, renowned as the father of Chinese rock, in 1989, and the song became a musical symbol of their defiance.

Cui was banned from playing large-scale concerts following the crackdown on the demonstrators in which hundreds, perhaps thousands of people were killed.

But Jonathan Campbell, the author of Red Rock, a history of the genre in China, told AFP: "Rock is not as dangerous as it used to be... I really do think there is a sense that it is OK now.

"The kids who grew up with Cui Jian are now parents... so priorities change and so do understandings and feelings about things like rock music," he said.

China has played host to an increasing number of foreign rockers, with the Sex Pistols' John Lydon playing earlier this year and Metallica appearing in Shanghai last week.

But some acts still face restrictions -- Shanghai band Top Floor Circus, whose satirical lyrics poked fun at government projects in the city, had concerts banned by police in 2009.

"Rock as entertainment is totally safe, but there are limits. Some things are OK but suddenly you bump up against the wall," said Campbell.

And while rock fans were once seen as rebellious youths hoping to alienate their parents, wannabe stars at the school have their families' full support.

"Children are under a lot of pressure," said Qi Yue, the mother of Cool's lead singer. "Rock allows them to blow off steam."

"Music brings them happiness," father Zhou Hongxin said. "We only have one child in each family, but by being in a band, it's as if they have sisters."

Weeks before the competition, Cool met at the school for a weekly rehearsal as their parents sat outside -- part of a regime which sees the children practice their instruments for up to two hours every evening.

Drummer Ma Ruisheng beat her sticks together before lead guitarist Wang Jiajun launched into the thumping riff from "I Love Rock And Roll" and the group erupted into giggles, drawing a frown from their teacher.

The school's fees -- about 200 yuan ($32) for an hour's lesson, plus the costs of equipment -- mean that most of Nine Beats' graduates are members of China's comfortably-off middle class, and have aspirations to match.

"Our dream is to release our own record, and travel the world performing in huge stadiums," said Wang -- as long as it does not interfere with their education.

"Homework comes first," said lead singer Zhou. "Not only has playing music not influenced our studies, it's actually improved our results."