Inharmonicity in other instruments

[Tom Cole]

Robert,

I'm having difficulty understanding what you mean by "any frequency can
be excited in a resonant system." Don't the resonances of a string limit
the vibrational possibilities? I've always believed that stiffness was a
major contributing factor in inharmonicity; that, along with striking
the strings with hammers as opposed to plucking or bowing. What is it
exactly that produces the harmonics? Don't the hammers simply excite the
harmonics that result from the strings own "resonant structure?"

Also, could you point me toward some source material on this subject?
I've never been exposed to anything of this sort.

 Robert Scott wrote:
> 
> ...In a piano and in other struck or plucked
> instruments, inharmonicity is possible because of the way in
> which the energy is converted into periodic oscillations.  In
> these instruments, an initial pulse of energy is applied by
> striking or plucking something that has resonances.  Since the
> initial pulse is not periodic, any frequency can be excited in a
> resonant system (like a string). In a piano string or in a bell,
> the resonances that support the different partials are essentially
> independent.  They superimpose on each other without really
> affecting each other. That is why the second partial can "ring"
> at a frequency that is unrelated to the fundamental.  What is
> surprising about piano strings is not that they have inharmonicity,
> but that the paritials are as close to true harmonics as they are...


-- 
Thomas A. Cole RPT
Santa Cruz, CA