Hi there, I have a scenario in which different frequencies will be played behind a curtain with a 2m opening. I would like to calculate the angle of diffraction for different frequencies played by the piano. One equation that I came across through research is Fraunhofer's Single Slit equation. (http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html) I am just curious as to whether I can apply this to sound even though it was developed for light waves. -Thank you in advance.