Incongruent Hobbit (or the malice of famous actors and modern music)

"[...]
If this is to end in fire
Then we shall all burn togetherWatch the flames climb high into the nightCalling out father, stand by and we willWatch the flames burn auburn on the mountain side [...]"

An absolutely gorgeous and infectious hooks galore soundtrack. I have been listening to it for the past couple of days and I find the voice, the pounding guitar beat, the echoes of the humble choir entwined superbly. If you have not listened to it yet, you can find it here:

I find it perfect as a solo song. Or, it could perfectly fit into a contemporary plot featuring a male character between 25-35 years old...either pursuing a heart or a career. The masculine voice crooning is too arousing and individualistic for a fantasy movie about dwarfs. This sensual voice does not belong to a song about dragons. Or at least, I cannot fancy a dragon when I hear his voice.
Also, the instruments. The main instrument of this soundtrack is acoustic guitar (there are some short chorus episodes of cello that I could detect). Guitar is a modern instrument, it has been invented at the end of the 18th century. One does not need to know when the guitar was created in order to feel the modern touch of this song. And it sounds amazing, no doubt. The strumming is clean, decisive and manly. However, the action in the Hobbit takes place between Dawn of Fairies and and the Dominion of Men. There is no chance a guitar can squeeze in those times. Both the movie and the soundtrack are brilliant, but together they accomplish a negative synergy as I feel disconnected from the movie and I cannot relate to the song after watching the Hobbit. 
Another, a slightly poignant moment that I have also experienced during Thor 2 (starring Natalie Portman in the main female role) was to see Evangeline Lilly...She was too familiar (after watching Lost) for an elf. I could not frame her in the Hobbit, her image reminded me of plane crashes, secluded island etc. and every theatrical move of hers in the Hobbit, seemed fake. Surely, not because she is not a good actor, but because being too famous she has already created a modern "image" that cannot be dimmed in 2 hours and framed in an absolutely different context. I personally think fantasy movies should star "fresh" faces with no history to create a realistic story.

This is my very own opinion and feeling and it might not be right, but this is still a point of view.