The mountain is the Lonely Mountain, the Kingdom of Erebor, the last dwarf kingdom in Middle Earth. This song describes the dwarves in the company of Thorin Oakenshield(son of Thror, son of Thrain, heir to the line of Durin, King Under the Mountain) in their quest to take back their homeland from the dragon Smaug. They are willing to die and burn together and even bring desolation fighting for what they lost.
"Keep watching over Durin's sons"
refers to the dwarves putting their leaders first, because all would be lost without them. "Durin's sons" are Thorin, and his nephews, Fíli and Kíli because they are the heirs to the throne. But the heirs would be just as lost without their people, "Oh should my people fall then surely I'll do the same".
"And as the sky is falling down, it crashed into this lonely town"
refers to Laketown, town of men that sits at the foot of the Lonely Mountain. If Smaug is awakened, it is sure to be the destruction of this place and it's people by the dragon's flames and ire, just as Dale before it.
The mountain is the Lonely Mountain, the Kingdom of Erebor, the last dwarf kingdom in Middle Earth. This song describes the dwarves in the company of Thorin Oakenshield(son of Thror, son of Thrain, heir to the line of Durin, King Under the Mountain) in their quest to take back their homeland from the dragon Smaug. They are willing to die and burn together and even bring desolation fighting for what they lost. "Keep watching over Durin's sons" refers to the dwarves putting their leaders first, because all would be lost without them. "Durin's sons" are Thorin, and his nephews, Fíli and Kíli because they are the heirs to the throne. But the heirs would be just as lost without their people, "Oh should my people fall then surely I'll do the same". "And as the sky is falling down, it crashed into this lonely town" refers to Laketown, town of men that sits at the foot of the Lonely Mountain. If Smaug is awakened, it is sure to be the destruction of this place and it's people by the dragon's flames and ire, just as Dale before it.