Recently, the web page Webislam, created by Spanish converts to Islam, reported that the score of the Nuba al-Istihlál of Avempace (11th century), arranged by Omar Metiou and Eduardo Paniagua, is very similar to Marcha Granadera (18th century), which is now the official anthem of Spain. That makes it the world's oldest song (about a thousand years old) used for the official anthem of a country.