Source: RotK movieverse
Disclaimer: Tolkien’s, these are his and PJ’s
There was a great deal gone before him: chased by Wraiths, Weathertop, the glorious vision that was Lothlorien… then being seized by Orcs, escaping into the woods by the skin of their teeth, walking with Ents, and Isengard… Frodo and Sam - not knowing where they were was a constant pain, like a littler hunger nothing can satisfy.
And here he was, dressed in black and silver, standing alone in a cold hall while his new-found sworn loyalty was sorely tested.
Denethor washed his hands of his son and sent him to his death… and now he must sing for him…