It's all about "A Hazy Shade of Winter" from their album 'Bookends.'

Partial Lyrics:

"Hear the Salvation Army band down by the riverside.
It's bound to be a better ride than what you've got planned.
Carry your cup in your hand and look around
Leaves are brown now and the sky is a hazy shade of winter"

 So button up, batten down and click on the buttons at the bottom.

Simon & Garfunkel, "A Hazy Shade of Winter":