1 string, 2 strings, 3 strings or more

[Kevin S. Riggs]

Hi folks!
 After the events of the past week I could use a nice distraction.
And since I love music and pianos, why not a piano related topic?
Are there any good books out there that give basic information
for a neophyte piano technician on simple things concerning piano
design and construction? Things like: what is the purpose of mutiple
strings in a unison. Does it increase sustain, loudness, or decrease
attack noise, etc. How do you obtain a particular harmonic balance/
sustain for a note played ppp through fff on a well designed piano
through voicing. You know, if you stick a needle in point "A" this
particular partial is reduced by so much. Or even, the size/stiffness/
mass/elasticity of a soundboard creates such and such a tone/amplitude
of a particular frequency. I am not aware of a proper treatise on such
matters. If anyone could give a hint on where to find the knowledge that
has been secured on any of these and like matters, I would be most
appreciative.

Thanks to all of the wonderfully inquisitive and generous
technicians out there for your response.

Kevin Riggs,
Associate in RTP, NC