Various musical instruments are used for the performance of music. Take orchestra for example, variety of instruments are being used in orchestra, from instruments that contain low frequency such as contrabasses and horns to other instruments that contain high frequency such as violin and flute. Moreover, the performance might be done with single musical instruments like Chopin's piano piece. Same thing can be said for music box since it is performed with single musical instruments. When it comes to 1/f Fluctuation, I thought it is disadvantageous for single musical instruments like the piano because the strength of the sound should be balanced and extended over a wide frequency band. But actually, it seems that my thought is not right. The bottom left figure shows the result of analyzing the first movement of Mozart's Concerto For Flute & Harp K.299. The bottom right figure shows the result of analyzing the piano piece of Chopin's Etude.

As a result, "1/f Fluctuation" is possible regardless of instrument variations.

I tried to compare the same tune that is performed by different musical instrument. Bottom right and left figures are the result of analyzing the same tune titled "Christmas Eve" by Tatsuro Yamashita. Bottom left is performed by music box and bottom right is performed by glass.

You can see that slope of the glass is more gradual and is close to "1/f Fluctuation". Also you can see that it is leaning stably to the low frequency band. By the way, it seems that the glass of Asahi Glass Company is being used for the performance.