Advice for a Tuning Setback

My friend Peter W. from London, Ealing who is a novice piano tuner asks me:

In the last few months, I have been having a setback in my tunings. I am experiencing a problem which is adding an extra hour onto my one hour and 45 minute tuning time.

I am assuming I am doing something wrong. I set the temperament first then usually do the bass next, but because of this problem I go first to the tenor and treble, and sometimes do a pitch raise in the high treble section (after the last break). By the time I complete the bass section, my area above the temperament is flat and occasionally my temperament is out.

My experience is different with each piano, but as always the treble section after the last break is always flat. This is always a problem when the pitch is 5 cents flat or lo-20 cents flat. Any piano which is over 20 cents flat I do a pitch raise and then a fine tune and I still encounter this problem. I always set the pins and pound out the keys to settle the strings.

Can you tell me what I may be doing wrong?

Answer:

Dear Peter,

I’m not sure I have the definitive answer to your problem, but I do have some ideas which may lead you to a solution.

In your message, you didn’t mention how you strip mute the piano, but from your problem I’m going to assume that you might be muting the entire piano and tuning the centre strings from the temperament to the top of the piano, then tuning the unisons. If this is the case, after tuning all the centre strings, you have only dealt with one third of the tension shift of the piano. When you then time the unisons, you add the remaining two-thirds of the tension which would cause your temperament and tenor sections to drop in pitch.

I prefer to strip-mute just the temperament octave. After setting the temperament on the centre strings, I then work my way to the top using rubber mutes and bringing up the unisons as I go. I sometimes have to follow an octave behind and touch up a few notes that slip here and there, but when I get to the top, I have dealt with all the tension changes and corrected any errors that might have slipped in. I then tune the bass which I find has very little effect on the treble tuning. I find that I can usually handle a pitch change up to about 10 cents with this method. When I am faced with a piano that is more than 10 cents flat, I do a complete pitch raise followed by a fine tuning.

The purpose of the first tuning is not to get the piano sounding good, but to get the tension averaged out with the piano at the proper pitch. We all realize that to do this, we must tune the piano above pitch to allow it to fall back where we want it. The difficult thing is to determine just how sharp we need to pull it. The general rule is that the piano will drop about 25 % of the amount it is raised. A piano that is 30 scents flat will need to be raised to 10 cents sharp to end up at the desired pitch.

The problem is that not all pianos behave according to the rule-some pianos fall less, some more, and some fall considerably more. Unfortunately, I can’t tell you how to predict which pianos are which because it is a very intuitive decision-making process, developed only after tuning many pianos. I can tell you that most pianos need a little extra compensation in the tenor section above the first break (the area with the last dampers). This section seems to fall more than the rest of the piano. To help you develop this skill yourself, I suggest keeping a log of each piano you tune, recording the starting pitch, the amount you pull it up, and the final pitch. After a period of time you can begin to adjust your pitch raises based on your own experience.

When I pitch-raise, I use a much different method than for fine tuning - I strip-mute the entire piano and tune aII the centre strings from the temperament up to the top. I then me all the right hand strings to the centre strings, removing the mute strip one note at a time, working from the top back down to the bottom of the temperament. I then tune my way back up to the top, tuning the left hand strings to the two open strings that are already tuned. I then tune the bass. I find that this adds the tension to the piano in a very even way which minimizes the amount that the piano drops.

This may not apply directly to your question, but you might also want to consider trying an impact tuning lever. I find that with this tool the pianos drop a little less and I don’t break nearly as many strings. I also get to sit down even when tuning the tallest old uprights.

I hope that I have given you some ideas which might help you solve you problem.

Good luck and let me know how things turn out.