The figure below shows the result of analyzing the Javanese court gamelan which is made up of chorus by male & female singers and gong performance.

Although there are some irregularities in the graph, the form of the slope is very similar to the 1/f Fluctuation. This result is something I did not expect since gong is a unique instrument to be used. I thought the form of the graph would be more unusual. Moreover, whether the tempo is slow or not does not affect the fluctuation so much.