Tuning (5/5)

How To Tune a Piano:

A Summary of Chapters 6 and 7 from "Piano Servicing, Tuning, and Rebuilding" by Arthur Reblitz

Part V of V

Yo' Mama's so fat, she can't jump to a conclusion.

Raising and Lowering the Pitch
Sometimes pianos are not well taken care of and go very badly out of tune.  If the strings are rusty, be sure to let each string down until it "ticks" as the rust breaks before trying to tune each string.  If a piano has gone at least a quarter step flat or sharp, it is probably necessary to raise or lower the pitch.  When string tension increases throughout the entire piano, the plate and frame flex a little more, and the bridges and soundboard get pushed further down.  Because of this, a flat piano will remain somewhat flat, and a sharp piano will remain somewhat sharp after a normal tuning.  In these cases, begin with a few rough tunings, spending no more than twenty minutes on each one.  If the piano is flat, the strings are not rusty, the pinblock and bass bridge are in good condition, and you know what you're doing, the pitch can be raised slightly above A440 without damaging the strings for the first tuning.  Aim to go over by about half as many cents as the piano has gone flat.  For example, for a piano that is 50 cents flat, aim the first tuning to be about 20-25 cents sharp.  Similarly, if the piano is 50 cents sharp, aim the first tuning to be about 20-25 cents flat.  When lowering the pitch, taper off the flatness towards the high treble and low bass.  The last half of the highest treble octave should remain at pitch.

Tuning Problems
A false beat is a beat within a single string.  False beats are typically found from the treble break through the middle of the highest octave.  Often, false beats can be corrected by ensuring that the vibrating sections of the strings are well seated at their termination points.  Rusty, kinked, twisted, or overstretched strings can also cause false beats.  To tune a string with false beats, lower the string until real beats are detected, and focus on these while raising the pitch.  Sympathetic beats are very soft, and are caused by ringing in the high treble.  To eliminate them, re-mute the high treble or the duplex string segments.  If one end of the piano goes out of tune while the other end is being tuned, the piano probably has a loose pinblock.  If the pitch doesn't change unless the tuning lever is moved a great deal, the pressure bar may be screwed in too far.  Raising it will help to equalize string tension.  When tuning two pianos together, they should be the same brand and model.  Tune each piano separately, and then compare each note with the help of an assistant.  Additional topics I refuse to cover, but which are included in Reblitz's Chapter 7, are: Tuning the Back Duplex Scale, Tuning the Mason & Hamlin Screw Stringer Piano, Tuning a Piano to an Organ, Tuning a Piano on a Bandstand, and Tuning Victorian Pianos.

Electronic Tuning Devices
Electronic Tuning Devices convert tones into visual patterns.  They are not useful in tuning an entire piano to a set of frequencies, as all intervals must stretched in reality due to inharmonicity.  If a piano were tuned to theoretical frequencies, the treble would be flat and the bass would be sharp.  Therefore, it is necessary to find the inharmonicity of each pitch and compensate accordingly when using an electronic tuner.  Here is one method that will produce acceptable results.
(It sounds difficult to me.)
Calibrate the tuner to A440.  Mute the center section of the piano and tune F2 to the tuner.  Measure the second partial, divide the stretch over the octave by twelve, and recalibrate the tuner sharp by that amount for each pitch in the temperament octave (F2-F3).  To tune the treble, set the tuner for F#3 and play F#2.  The tuner will read the inharmonicity of F#2's second partial.  Recalibrate the tuner so that F#2's partial reads in tune, and then tune F#3 to the tuner.  Tune by octaves with this method throughout the rest of the treble.  To tune the bass, reverse this procedure.  Calibrate the tuner so it is in tune with E3.  Then play E2 and tune it so that its second partial reads in tune to E3.  Continue tuning by octaves this way down through the bass.

Why Pianos Go Out of Tune
The changes in position of the frame, plate, pinblock, tuning pins, bridges, and soundboard can all contribute to a change in string tension, which makes a piano go out of tune.  A decrease in humidity will cause less crown in the soundboard, which will cause the piano to go flat, while an increase in humidity will cause the piano to go sharp.  Temperature changes don't have as strong of an effect as humidity, but they matter.  New piano wire is very elastic, causing pianos to go flat frequently for a few years.  Old pinblocks can lose their grip on tuning pins, causing pianos to go flat.  Also, the louder and more frequently a piano is played, the more out of tune it will become.

If you've made it all the way here from Part I, you deserve one final joke and a drink.  I'll provide the joke.  I loved writing this series, but proofing it was a total bore.  Reading it for the first time would be even worse.

There was once a pianist who was so good, she claimed she could tame wild animals.  People wanted to see if this was true, so they took her into the jungle and set her in a clearing with a piano.  As she started playing, all the rhinos, tigers, elephants, hyenas, warthogs, and so forth emerged and sat down peacefully to listen to the beautiful music.  Then the lion appeared.  He entered the scene, immediately pounced on the pianist, and violently ate her.  An angry monkey approached the lion and accusingly asked, "Why would you do that?"  The lion put one paw behind his ear and responded, "Pardon?"