Aha!
After thinking and thinking (this is not something one can look up in the indexes

), I think I’ve got it!
What is the song “Frodo of the Nine Fingers and the Ring of Doom.”?
“‘Lo! lords and knights and men of valor unashamed, kings and princes, and fair people of Gondor, and Riders of Rohan, and ye sons of Elrond, and Dúnedain of the North, and Elf and Dwarf, and greathearts of the Shire, and all free folk of the West, now listen to my lay. For I will sing to you of Frodo of the Nine Fingers and the Ring of Doom.’
And when Sam heard that he laughed aloud for sheer delight, and he stood up and cried: ‘O great glory and splendour! And all my wishes have come true!’ And then he wept.”
(The Field of Cormallen, Return of the King, J.R.R. Tolkien)