The Fall of Gil-galad was a poem sung by Sam Gamgee before he and the three other Hobbits, led by Strider, reached Weathertop. The lay known as "The Fall of Gil-galad" had been written in ancient times, and spoke of the death of the Elven High King Gil-galad, who was in battle with Sauron during the Battle of Mordor. Sometime during his stay in Rivendell, Bilbo translated it from an older tongue, probably Quenya. The song is incomplete, as Sam didn't want to learn the rest of the verses, as they dealt with Mordor and the war.
Gil-galad was an Elven-king.
Of him the harpers sadly sing;
the last whose realm was fair and free
between the Mountains and the Sea.
His sword was long, his lance was keen.
His shining helm afar was seen;
the countless stars of heaven's field
were mirrored in his silver shield.
But long ago he rode away,
and where he dwelleth none can say;
for into darkness fell his star
in Mordor where the shadows are.