I have always wanted to understand the result in this paper, since it is one of the first major publications of the first Indian to win a Nobel prize in science

I have always wanted to understand the result in this paper, since it is one of the first major publications of the first Indian to win a Nobel prize in science. Can you point out to some more basic acoustics? I've wondered about what similar results hold for Idakka [1], a drum played in Kerala, and the talking drums of Western Africa [2]. [1] https://www.youtube.com/watch?v=kaozNblda54 https://www.youtube.com/watch?v=kaozNblda54 [2] https://www.youtube.com/watch?v=B4oQJZ2TEVI https://www.youtube.com/watch?v=B4oQJZ2TEVI