I visited Whitechapel Bell Foundry a few years ago, where they explained how part of the bell making process is to tune each bell to play a chord.
The unique sound of Big Ben is because the officials at the Palace of Westminster ignored the experts' instructions (some things never change) and used a hammer that was too heavy and with too long a drop. Which cracked the bell.
(This is after doing the same with the original bell and breaking it. What is it called when you do the same thing again and expect different results?)
The bell was then turned through 45 degrees so that the part the crack is on will vibrate the least. So it chimes, but the tone is not what the bell foundry intended it to be. The sound though is instantly recognisable as Big Ben.
Biting the hand that feeds IT
