When Katy Perry cries in Beijing

Katy Perry cried.

On a recent Sunday afternoon, the pop superstar attended a rehearsal of the China National Orchestra, the country's leading traditional folk music performance group, in Beijing.

When more than 90 Chinese musicians from the orchestra played her hit song, Roar, with ancient Chinese instruments like the guzheng (Chinese plucked zither), erhu (two-stringed bowed instrument) and pipa (four-stringed plucked instrument), she sat at the back of the theater, wiping her tears.