The period has also seen numerous technological developments in how music is spread and listened to. Gramophone records were already made in China by 1902, and Chinese radio began in the 1920s. Both media concentrated primarily on entertainment music welcomed by the urban classes, including much traditional opera and ballad singing, but also some new film and dance songs. In 1949, all radio services in China were placed under strict governmental supervision (Hamm 1991:2) and more focus was put on disseminating the messages the government thought the people should hear, including some massed songs and other revolutionary material. The implementation of economic and political reforms in the late 1970s brought more relaxed cultural policies. Simultaneously, the importation of easily accessible listening equipment, i.e. cassette technology, heightened users' control over music consumption. Entertainment music-which had continued to develop in Taiwan and Hong Kong-made its way back into the Chinese mainland once again. Today's listeners have access to the same technological tools available outside the nation, although political restrictions can sometimes make themselves apparent. In 2018, for example, the government acted to restrict the rap scene, worrying that the singers portrayed negative role models to their fans, and some websites like YouTube are blocked in China (although there are Chinese equivalents).