shiremaiden:

LOTR CHAPTERS: THE RETURN OF THE KING – Chapter Five: The Ride of the Rohirrim

But at that same moment there was a flash, as if lightning had sprung from the earth beneath the City. For a searing second it stood dazzling far off in black and white, its topmost tower like a glittering needle; and then as the darkness closed again there came rolling over the fields and great boom.
   At that sound the bent shape of the king sprang suddenly erect. Tall and proud [Théoden] seemed again; and rising in his stirrups he cried in a loud voice, more clear than any there had ever heard a mortal man achieve before:
                     “Arise, arise, Riders of Théoden
                      Fell deeds awake: fire and slaughter!
                      Spear shall be shaken, shield be splintered,
                      A sword-day, a red day, ere the sun rises!
                      Ride now, ride now! Ride to Gondor!”

With that he seized a great horn from Guthlaf his banner-bearer, and he blew such a blast upon it that it burst asunder. And straightway all the horns in the host were lifted up in music, and the blowing of the horns of Rohan in that hour was like a storm upon the plain and a thunder the mountains.