A national anthem is a song for a people
It is actually already in the name: National anthem: A Song of the people. A national anthem is often thought of as a state or nation, but it can also be a region or even a village. Under the influence of the emerging nationalism, the folk songs came to the attention in Europe in the 19th century: most of the European folk songs come from that time. Some folk songs were once started as a battle song and later became an official anthem. The Wilhelmus is an example of this, only officially the Dutch national anthem in 1932 but is still known as the oldest national anthem in the world (or one-after-oldest) because the text actually comes from the 16th century. In General, a folk song is easily written so it can also be nagezongen, it also often has a rousing melody (here too The history of a battle song is recognizable).
The Wilhelmus-Dutch national anthem [YouTube] GwBrR_G70RE [/youtube]
Other folk songs [YouTube] 71EEC8986E07BC15 [/youtube]