Please mute a music instrument.

请减低乐器的声音。

I know in playing music instrument to obtain a tenth grade certificate is rather difficult.

但我知道在演奏乐器方面要获得一个十级证书是相当难的.

This article sets forth the significance and necessity to establish China national music instrument acoustic standard.

本文阐述了制定民族乐器音响标准的意义与必要性。