“ What made us feel that this is “actually the same melody”? The key word is once again ratios. The human ear and brain, it turns out, recognize two note sequences as “the same melody” when the ratios between their note frequencies are kept the same. And this is indeed exactly what happened: In both melodies, the ratio between the first and the second notes is 2:3, and the ratio between the first and the third is 3:5.
