Karen Hopper, one of the members of the Choral Arts Society of Washington, accidentally dropped a musical score from an enclosure high above the stage during a rehearsal in Qingdao, in East China's Shandong province.
A musician from Qingdao Symphony Orchestra picked it up and returned the page to Hopper.
"You know, in Chinese tradition, when somebody does you a favor, you should treat him to dinner," Zhang Guoyong, artistic director of Qingdao Symphony Orchestra, jokingly told her as he handed back the score.
The musicians were at Qingdao Grand Theater to prepare for a concert series by the Chinese orchestra and the US chorus group.
"Yes, I will. How about tomorrow night?" Hopper, the 25-year-old singer, replied.
Hopper started singing at 5, and joined the Choral Arts Society of Washington after college.
A few laughs later, Zhang and Hopper got back to rehearsing for the Two Countries, One Stage concert.
The concert made its debut in Qingdao on May 28 and was performed at the 15th Meet in Beijing Arts Festival on May 30. It will tour Shanghai, Guangzhou and Hong Kong.