TIME was when the cadres in Beijing considered anything connected even vaguely with pop culture as downright spiritual pollution. But times they are a-changing. Now the Chinese authorities are actually looking to the pop world to help them out of tight corners - as Hit Radio, the Canto-pop channel of Metro Radio can attest. The National Sports Committee of the Cultural Department has asked Hit Radio to organise a concert tour of Hongkong pop artistes to help raise funds for China's Seventh National Games. With China bidding for the 2000 Olympics to be held in Beijing, the National Games has become an important indicator as to its ability to stage the event. The tour will be staged by Hongkong Manoton Entertainment, the concert promotion arm of Metro Broadcast recently formed by Metro boss Craig Quick. This time around, the popsters exercising their tonsils for the cause will be from the second rung of Canto-pop, with the ''Four Kings'' - Andy Lam, Aaron Kwok, Jacky Cheung and Andy Lau - probably being held in reserve to aid the Olympic event. Spread over six major Chinese cities between May and August, the concerts will be compered by Hit Radio DJs, and staff from the station will provide the technical back-up. Among the local artistes performing are Vivian Chow, Lui Fong, Prudence Liu, Angela Pang and rock group Grasshopper. Elderly cadres are bound to shake, rattle and roll their heads in disbelief at changing values. If Chairman Mao was alive today he would be turning in his grave.