Dec 14, 20223 min
Updated: Sep 13, 2023
By Kate Redding
Many piano technicians use test blows as a method to gauge tuning stability. As a new tech, I relied on test blows to ease the fear that my tuning wasn't stable or good, but it felt unnatural pounding a note at a volume that made it difficult to listen carefully.
Musicians are taught not to hit a piano, yet technicians are tuning this way. If we developed a stable tuning style that relied on fewer test blows, could the result be better for both the technician and the piano?
Definition: A test blow is a forceful or repeated pounding of the key.
A stable tuning can withstand very powerful playing, and tuning stability improves when:
The tension on the front string is higher than the tension on the speaking length.
The friction at the bearing points does not cause the string to bind or render poorly.
The tuning pin is seated correctly in the pin block.
The tuning pin is turned accurately.
The humidity and temperature are stable.
Test blows can be a source of tuning instability when these conditions are not met. If test blows are knocking notes out of tune, take some time to:
Lubricate the stringing felt under the front strings.
Carefully massage the string along the front length with a brass drift or a hammer shank.
Seat high tuning pins with a pin punch and pin block support, and snug the pin coils.
Seat the strings on the bridges.
Change the angle of your tuning lever on the tuning pin.
Dan Levitan provides an excellent description of the behavior of the string, the tuning pin, and the tuner's hand in Part Two of his book, The Craft of Piano Tuning.
Most piano technicians acknowledge the need for a forceful blow at least some of the time, but it's easy to creep into pounding range. So here is my argument for using fewer, less aggressive test blows:
Test blows can fatigue a piano technician through repetitive motion injury of the hand and arm and the aural fatigue produced by repeated percussive strikes at close range. As the body fatigues, it becomes hard to maintain a good posture and tuning accuracy. My ability to detect subtle regulation differences improves when I use a softer touch
The hammer's shape and the strike point surface are crucial for tone. Aggressive test blows are not good for the shape of the piano hammer, which is meant to contact the string precisely. If you want to maintain a narrow strike point on the crown of the hammer and a viable surface for voicing, adopt a style that relies on tuning lever technique for tuning stability.
Pianos are built to withstand years of use, and your clients are keen to keep their instruments in good condition. Pounding the keys stresses the hammer flange center pin, shank, string, etc. Your client will thank you for tuning their piano without hitting it.
The power of a forceful player is challenging to replicate. A test blow to a single key cannot reproduce the energy or vibration of the piano as it is played. It helps to get the piano vibrating in every range. When preparing a piano for a performance, I use the forearm smash described in Steve Brady's Under The Lid.
The point of the forearm smash is to get every string vibrating at once, at high volume. It's cacophonous but lasts only a minute. Once the volume dies down to mezzo piano, release the sustain pedal. You can observe the effectiveness of the dampers with a slow release of the sustain pedal at this volume.
While some pianos can withstand aggressive playing better than others, only some pianos are capable of pitch accuracy with test blows. The quality and condition of the piano play a large role in stability; the soundboard, the rim, and the strings are all sources of tension in a piano.
When you use an overpull method, you compensate for an intended direction in pitch. However, setting the string at this intermediate pitch is counterproductive because the goal is to let the string drift to the intended pitch. Therefore, test blows should not be used to set the string during pitch correction.
If you hit a piano, it will never forgive you. If your tuning style is heavy-handed, pull back. Adopt a keystroke that does not exceed mezzo-forte, and use fewer test blows daily.
A good tuning lever technique is more effective than a test blow to stabilize the tension along the string's speaking and non-speaking lengths. Instead of using a pounding technique, practice raising the arm and allowing it to fall on the key with the force of gravity. Practice using fewer strikes to the key as you tune each string, and listen for the attack, bloom, and sustain. This way, you will develop an appropriate style for producing a good tone for tuning and voicing.