Most of the songs that Fa Zi played were originals and he could improvise a new one on the spot. That was unique for him since in China most of the musicians you came across were classically trained and could read music but had never been taught much in the way of composition for personal expression.
Of course every musician dreams of writing something touching and there is always self-expression going on. But Fa Zi excelled at it in a way that was unique and synthesized western rock and roll into it all successfully.
From my experience in China (perhaps due to the way the school system and society at large are organized around listening, repeating and obeying orders along a family structured pecking order rather than free-thinking creativity to a great degree) most Chinese were loath to publicly stand out, speak their minds, or offer a strong point of view.
(I say “publicly” since naturally everyone has a strong opinion. The Chinese simply have a tradition that it stay within the hutongs and behind strategically closed doors rather than have it worn on the sleeve like so many maudlin westerners do.)
And, in the great tradition of the rock and roll noble savage, Fa Zi didn’t need training. The guitar was just waiting there to be picked up. And, as DJ Youdai noted, anyone can play guitar.
Fa Zi of course knew and worked with performers who had trained at the music academies such as Beijing Rep (which Youdai and others on the scene attended, developing a healthy scene there) and they could play classical instruments as well as western ones if they wanted to.
But they seemed, I don’t know, timid in terms of the boldness of their own personal self-expression. They did not go out and buy a Marshall stack, nor were they fascinated with stadium-sized volume, feedback, and Jimi Hendrix as much as Fa Zi and his friends were in the band at Yuan Ming Yuan. It was really Fa Zi’s ability to express himself freely and creatively, sometimes in English, which set him apart from the many other musicians in Beijing. He was working originals during a moment in Chinese history when it was nearly impossible to get heard doing so.