Elven Hymn to Elbereth is the song that the traveling Elves, lead by Gildor, are singing when Frodo Baggins, Peregrin Took, and Sam Gamgee pass through. The book says that the song is in the elven tongue, Sindarin, but the sound shapes itself in their heads into words.
Snow-white! Snow-white! O Lady clear!
O Queen beyond the Western Seas!
O light to us that wander here
Amid the world of woven trees!
Gilthoniel! O Elbereth!
Clear are thy eyes and bright thy breath!
Snow-white! Snow-white! We sing to thee
In a far land beyond the sea.
O Stars that in the Sunless Year
With shining hand by her were sown,
In windy fields now bright and clear
We see you silver blossom blown!
O Elbereth! Gilthoniel!
We still remember, we who dwell
In this far land beneath the trees,
Thy starlight on the Western Seas.