Proclaiming Liberty, part III

So…what does the Liberty Bell SOUND like? Thanks to a research team of grad students at Pennsylvania State University, we’ve got an educated guess!

Hmm. That’s an interesting sound, isn’t it? Kind of crunchy. A neutral observer would say that it doesn’t follow the typical profile of partials in bells. Others may put it another way—it’s out of tune!

Wavanal, our handy-dandy bell tone analyzer, tells us that these are some of the partials for this rendering of the Liberty Bell. The strike note, or the tone that we primarily hear, is E-flat. This is not the same as the lowest partial shown, the hum tone; in fact, the strike note often coincides with the second lowest partial shown, the prime.

liberty bell partials on staff

Compare this to a standard bell’s arrangement of partials for a bell with a strike note of E-flat.

standard E-flat bell partials on staff

If you can’t read music, no worries. You can still see a critical point of deviation. There are three E-flats in the partials of the standard bell, while these three partials are all different notes in the Liberty Bell. For all you music readers out there, you may also notice that the standard bell’s partials are tuned to a minor triad. The Liberty Bell’s partials are not. The Liberty Bell’s lack of an agreeable-sounding chord in these overtones partially explain its out-of-tune sound. We’ll explore bell tuning more next time.

5 Replies to “Proclaiming Liberty, part III”

  1. Why might the Liberty Bell (a brand new, pre-cracked Liberty Bell?) sound out of tune? Has anyone speculated? The result of bad workmanship, perhaps, or was this intentional?

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  2. Sources say that the alloy of bronze used to make the bell had an incorrect proportion of copper, tin, and lead, which resulted in a very brittle bell from Whitechapel. When Pass & Stow adjusted the alloy for their two recastings, they still didn’t get the alloy proportions right, and the bell was still brittle. This can affect the sound of the bell. Pass & Stow were inexperienced bell founders, so I would speculate that they hadn’t quite mastered the art of bell tuning when they tuned the Liberty Bell, just as they failed in producing a good bronze alloy.

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    1. Answers lead to questions, why would the Founders use an inexperienced bell founders for their vital symbol? No money, didn’t know any better, no one else available?

      Also, what is a partial?

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  3. The Americans decided they would rather have a loyal American this side of the pond recast the bell, rather than having Whitechapel try again (since they did such a poor job the first time around). Pass & Stow were willing and available, so they got the job. There were not very many experienced bell casters in the New World at the time.

    A partial is an overtone, or a pitch that is part of the tone that we hear in a musical sound. When an instrument plays a pitch, let’s say A, we are not hearing a pure A in the sense that there is only one sine wave vibrating at 440 cycles per second (hertz). There are many other vibration cycles per second contained within that note, creating higher frequencies that are not as prominent as the main A pitch that we hear. These are called partials. The partials for a note are basically the same for any musical instrument that uses an air column or string. The relative volumes of the various partials, however, differentiate the sound of one instrument from another, which is what we call timbre. This is how we can hear the difference from a trumpet from a piano from a violin, etc.

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