http://www.youtube.com/watch?v=eZbA6nMqV1g
The second night in Bombadil's house, Frodo dreams of a song that "seemed to come like a pale light behind a grey rain-curtain, and growing stronger to turn the veil all to glass and silver, until at last it was rolled back, and a far green country opened before him under a swift sunrise."
http://fathom.bandcamp.com/