"Oranges and Lemons" is also a nursery rhyme, and a children's song. It depicts the bells of the churches of London talking to each other. In structure, the piece is simple, rhythmic, and melodic, with death at the end, just like most nursery rhymes. The current song is actually a shortened version of the earlier rhyme.
I remember this song from a record of the Cambridge Boys Choir we had when I was very small. It actually sounded like a song, not like a sing-song, which was all I ever heard at that point. It sounded more real than anything.
During the London Blitz of WWII, St. Clement's Danes and St. Mary-Le-Bow, both built by Christopher Wren, were destroyed. News reports were kept as anonymous as possible at this time, to avoid any intelligence escaping across the Channel. So the wireless reports on the bombing of St. Clement's said only that the church of oranges and lemons had been destroyed.
Oranges and lemons
say the bells of St. Clement's
You owe me five farthings
say the bells of St. Martin's
When will you pay me?
say the bells of Old Bailey
When I grow rich
say the bells of Shoreditch
When will that be?
say the bells of Stepney
I'm sure I don't know
says the great bell of Bow
Here comes a candle
to light you to bed
And here comes a chopper
to chop off your head.
Addendum, 29 Oct 2003: Gritchka says "St Clement's Danes and St Mary-le-Bow both still stand: St Clement's was damaged by enemy action and the scars are preserved, but neither was actually destroyed, just damaged." See, this is what I get for writing things about London when I've never been there.
Sources:
http://www.whenigrowrich.com/about/churches.htm
http://ingeb.org/songs/gaygoupa.html