A band composing of students from Huishi Middle School rehearses for a performance in Lanzhou City, capital of northwest China's Gansu Province, Dec. 17, 2012. The student band received an invitation letter from the art director of the Vienna Children's Choir, inviting them taking part in the Chinese Festival held in Austria in January, 2013. (Xinhua/Chen Bin)

Students from the student band of Huishi Middle School clean the musical instruments in Lanzhou City, capital of northwest China's Gansu Province, Dec. 17, 2012. The student band received an invitation letter from the art director of the Vienna Children's Choir, inviting them taking part in the Chinese Festival held in Austria in January, 2013. (Xinhua/Chen Bin)

A band composing of students from Huishi Middle School rehearses for a performance in Lanzhou City, capital of northwest China's Gansu Province, Dec. 17, 2012. The student band received an invitation letter from the art director of the Vienna Children's Choir, inviting them taking part in the Chinese Festival held in Austria in January, 2013. (Xinhua/Chen Bin)

Members from the student band of Huishi Middle School show the invitation letter from the art director of the Vienna Children's Choir in Lanzhou City, capital of northwest China's Gansu Province, Dec. 17, 2012. The student band received an invitation letter from the art director of the Vienna Children's Choir, inviting them taking part in the Chinese Festival held in Austria in January, 2013. (Xinhua/Chen Bin)

Bao Han(2nd R), a member of the student band of Huishi Middle School, discusses about music score with his companions in Lanzhou City, capital of northwest China's Gansu Province, Dec. 17, 2012. The student band received an invitation letter from the art director of the Vienna Children's Choir, inviting them taking part in the Chinese Festival held in Austria in January, 2013. (Xinhua/Chen Bin)