Variation of temperature

[Newton Hunt]

Temperature rare effects piano pitch unless sunlight or very hot spot lights
shine on the strings which temperature change would be difficult to measure
without a laboratory setup.

If you are looking for data concerning the change of pitch relative to humidity
changes there was an aritcle pulished by Don Galt a few years ago.

If this is your interest I could look it up in the journal index for you.
      Newton
      nhunt@rci.rutgers.edu