Lament for the Rohirrim
This article describes a concept which is mentioned in J.R.R. Tolkien's works, but was never given a definite name.
Lament for the Rohirrim, also identified by its first line, Where now the Horse and the Rider?, is a song about Eorl.
Where now the horse and the rider? Where is the horn that was blowing?
Where is the helm and the hauberk, and the bright hair flowing?
Where is the hand on the harpstring, and the red fire glowing?
Where is the spring and the harvest and the tall corn growing?
They have passed like rain on the mountain, like a wind in the meadow;
The days have gone down in the West behind the hills into shadow.
Who shall gather the smoke of the dead wood burning,
Or behold the flowing years from the Sea returning?
 Portrayal in adaptations