An aria from a Croatian opera, "U boj, u boj", is sung by Japanese choirs since WW1. It was first thought to be Czech though because Czech sailors played it whi

An aria from a Croatian opera, "U boj, u boj", is sung by Japanese choirs since WW1. It was first thought to be Czech though because Czech sailors played it while repairing their ship ashore in Kobe after the great war. https://en.m.wikipedia.org/wiki/U_boj,_u_boj https://en.m.wikipedia.org/wiki/U_boj,_u_boj It is sung in Croatian! https://youtu.be/uqQf_92dgHM https://youtu.be/uqQf_92dgHM