The Song of Gondor was sung by Aragorn on his quest to rescue Merry and Pippin from the Orcs. He sings it after the death of Boromir (who perished at Amon Hen whilst battling Uruk-Hai), and it showcases his great regard for Gondor. It is unknown whether or not the song is a common one amongst the Men of Gondor, or whether Aragorn developed it himself.
Gondor! Gondor, between the Mountains and the Sea!
West Wind blew there; the light upon the Silver Tree
Fell like bright rain in gardens of the Kings of old.
O proud walls! White towers! O winged crown and throne of gold!
O Gondor, Gondor! Shall Men behold the Silver Tree,
Or West Wind blow again between the Mountains and the Sea?