Check out these three anthem stamps- something's not right in the picture. Stamps from Nicaragua containing the score of France's La Marseillaise? Italian stamps with the score of Poland's national anthem and a stamp from Mexico featuring the national anthem of the Dominican Republic? Stamps of national anthems are usually issued by the country who owns the anthem, but not in this case. These are real anthem stamps containing the score of the national anthem.
To my knowledge, Nicaragua has not even issued a stamp of its national anthem. Italy has issued a stamp of its anthem lyricist, Goffredo Mameli, but not an anthem score. The Dominican Republic is one of the few countries that has issued several anthem stamps (at least 3, I think). I really don't know the reason why these countries featured the national anthem of other countries. Please email me if you know why or if your have other anthem stamps not featured here.