Well, that explains ... wait.

Having heard "God Save the Queen" last year, and "House of the Rising Sun" recently coming from the organ at church, I approached the organist to ask him whether he knew he was playing "House of the Rising Sun"—perhaps there was a hymn that was just markedly similar.

"Oh, that's for the victims of the Hurricane Katrina. I know it's not terribly appropriate for church, but I don't think anyone besides you and Gregory notices. I like the chord progression."

I gaped and gawked, but managed not to laugh in his face.