Stage light slump

[Tom Cole]

Dear List,

Reading some posts regarding pitch-guessing or "overshoot" when
pitch-raising reminds me of a related consideration alluded to in a
recent post. The concert instrument you carefully tuned to A440 during
the cool, damp morning by evening has fallen a hertz or two at A4, the
tenor even more and the octaves across the break are beating noticeably.
The soundboard has apparently been parched by the heat of the stage
lights causing the uneven out-of-tuneness.

Question: do any of you anticipate "stage light slump" by putting a
tolerable "hump" in the middle of the tuning?

You may accuse me of being way too fussy - the two words "solid unisons"
come immediately to your lips. But I do aspire to the _art_ of tuning,
even though there may not be many in the audience who are going to
appreciate it consciously. If only for the reason of attracting the
business of discerning musicians, I want my best efforts to be displayed
on my concert tunings.

What I try to do is to make the tuning _unnoticeable_, to paraphrase
Horace, and so I wonder what others have done to cope with or maybe
control temperature changes on the concert stage.

Tom