Oddly enough on Monday night, Alan Price ex Animals (who made the song as famous as it is) was on BBC radio 2 and the whole interview can be found on BBC i-player.He was saying the song was originally English. 16 th Century about a brothel in London. It was then taken across to the states. There is was transformed to the present song about a brothel in St Louis or San Francisco.<http://www.bbc.co.uk/iplayer/search/?q=alan%20priceP> It was common to have suns on houses as a reminder of pagan days he said.