Excerpt from upcoming intonation book: HOW TO TUNE A WIND INSTRUMENT WITH A PIANO

HOW TO TUNE A WIND INSTRUMENT WITH A PIANO

The physics of instruments:
Winds do the opposite of string instruments in various temperature differences.
Hot weather – Piano strings and stringed instruments go flat because the string stretches
Cold weather – Piano strings and stringed instruments go sharp because the string contracts
High humidity causes a pianos soundboard to curve and expand which adds more tension to the strings which causes them to go sharp. Conversely, low humidity causes a piano soundboard to contract which releases some tension which causes it to go flat.
Note: If pianos have been tuned incorrectly, it will usually be flat (strings stretch with use), therefore, a poorly tuned piano on a hot day will be substantially flatter than a piano tuned at A = 440.

It is not correct for the piano to play first. This is a good example of when a good ear works against the musician.
Musicians will be lip the note in the direction of the piano note, not giving the musician an accurate tuning assessment.

Correct procedure to tune with a piano:
1. Performer and instrument is warmed up
2. Performer plays before the piano
3. Piano plays tuning note (see “preferred tuning note”)
4. Performer adjusts accordingly. If sharp = pull out, if flat = push in
5. Repeat the same process until tuning becomes beatless
6. Accompanist presses right pedal, performer plays tuning note which creates the sympathetic vibration from that note and overtones. This sympathetic vibration should clearly ring out from the piano if performer is perfectly tuned. This last step should be practiced in order to become accustomed to this ringing sound.

In reality, a performer will typically stand in the waiting area for several minutes prior to entering the performance room. It is at this time that it is crucial for the musician to continue to blow air through their instrument to keep it warm, otherwise, the instrument will flatten and the result will be that the performer will play flat for their tuning and push in, making them sharp for the entire performance. All musicians must be aware of the temperature differences between the warm-up location, hallway, and performance location and may need to tune again between movements
or pieces.

Possible help
Taking a walk through all areas, if possible, prior to the performance would be recommended to note these differences.

Tuning with the performance piano prior to concert

Note: high humidity expands the crown of the piano and pushes the bridge even more against the strings, therefore,
it stretches the strings and causes the pitch to rise.