Most nation-states have anthems, defined as "a song, as of praise, devotion, or patriotism"; most anthems are either marches or hymns in style. A hymn can become a national anthem by a provision in the state's constitution, by a law enacted by its legislature, or simply by tradition. A royal anthem is a patriotic song similar to a national anthem, but it specifically praises or prays for a monarch or royal dynasty. Such anthems are usually performed at public appearances by the monarch or during other events of royal importance. Some states use the royal anthem as the national anthem, such as the anthem of Jordan.