Are the elves in The Hobbit different than the ones in LotR?

[Knight of Gondor]

The elves in The Hobbit are interestingly different in Rivendell than in LotR, you notice? They're jolly, silly, singing silly songs worse than Larry from VeggieTales! I'm guessing perhaps they were kind of solemned up by circumstances surrounding their existance, like maybe they were about to face war. I don't know, but they sure seem different (a better kind of different) in the movie and LotR books...I can't imagine the elves of the movie singing songs like they did in The Hobbit, can you?

Oh yeah, and what does everyone think about Santa's elves? I think maybe they were an accursed breed, dispelled from Middle-Earth after some sort of rebellion, and deported to the North Pole where they repented and set about making kids happy all around the world to make right the wrongs they commited. But it's too bad that those who haven't seen the movie think that elves are those weird creatures of Santa's!