noise to signal

Why is this man smiling?

There I was this morning, standing on a crowded bus full of wet, crabby people, the windows steaming up from our breath condensing against the cold leaking in from the outside... smiling and bobbing my head cheerfully.

Why?

Because Desmond Dekker was singing sweetly in my ears, and I had no choice but to pay attention, from one happy island boy to another:

Come on, all you people
Come on, before it's too late
Because I and we are going, and we must rejoice
Come on, before it's too late.

That's the refrain from Mount Zion, by the way.