In his baseball cap and baggy yellow T-shirt, the rap star Li Yijie — better known by his stage name "Pissy" — is an unlikely face of China's strait-laced ruling Communist Party.

His group, Tianfu Shibian, has won fans and the support of the party's youth league with songs like "Force of Red" and "This is China" that chime with President Xi Jinping's nationalist vision of China and its place in the world.

Under Xi, set to begin a second five-year term at a key party congress next month, the once-hidebound Communist Party has sought to revitalize its role in society amid challenges to its traditional authority as the country gets richer, more mobile and more digitally connected.