"Oj, svijetla majska zoro", or in English, "Oh, bright dawn of May," is the national anthem of Europe's now second-newest independent state, Montenegro. It is also quite catchy. It's existed in several forms since originating as a folk song, but the newest lyrics were adopted when the anthem itself was officially adopted, in 2004. At that time Yugoslavia was dissolved into the State Union of Serbia and Montenegro (which itself dissolved in 2006 after Montenegrins declared independence). The independent Montenegrin principality which existed before World War I used a different anthem.
My favorite Montenegro fact is that the name Montenegro ("Black Mountain") is often translated into other languages literally--English, which uses the Italian name, is an exception. In Montenegrin/Serbian, the name is Crna Gora; in Turkish, Karadağ; in Albanian, Mali i Zi.
There are four verses to the anthem; some of the lines are repeated in a certain pattern, however. For the full lyrics, see the Wikipedia article.