Re: Do guitar picks affect the resonant frequency of a string?

As far as I can tell, the answer is no, sort of.  If you use a pick to 
pluck a guitar string anywhere along its length, the frequency is the 
same.

However, the timbre (tone quality) will be different depending on where 
you pluck the string, even though the frequency is the same.  The timbre 
is created by the strengths of different frequencies in the overtone 
series, so yes, you can say that the pick affects those frequencies.

But if by "resonant frequency" you mean the frequency you can hear (the 
string's given note name) or the physical resonance of the body/neck/etc. 
of the guitar, the answer is no.