Robert Estrin - piano expert

What is Stretch Tuning?

Learn the basis of the musical temperament

In this video, Robert talks about "stretch tuning", which is the basis of the musical temperament - the universally adapted tuning of the modern musical instruments.

Released on April 5, 2017

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DISCLAIMER: The views and the opinions expressed in this video are those of the author and do not necessarily reflect the views of Virtual Sheet Music and its employees.

Video Transcription

Hi, this is Robert Estrin. Welcome to Virtual Sheet Music and Today, a really fascinating subject, what is stretch tuning? Now when I describe what this is to you, you're going to be amazed, some things that you may not ever been aware of. Well, first we have to talk about, what is pitch? Pitch is actually the ability of your brain to count sound waves. When you hear an A like the orchestra tunes to A440, what that really means is there are 440 vibrations per second and we perceive that as the sound of A. If you double the frequencies you'll get a A an octave higher, 880 cycles per second, and this is what pitches really are about.

Now, there are tuners that can also measure these frequencies with absolute precision, even more precisely than the human ears are capable of hearing. But it goes much deeper than that. Because if you were to play with a tuner, and play perfectly in tune every octave, when you got to the higher octaves, would sound flat even though they'd register perfect on the tuner. The proof of this is if a violin were playing in the very high register, or a piccolo in the orchestra, if they were to play dead center to a tuner with absolute perfect precision, it would sound hideously out of tune. Now how can this be? Well the fact of the matter is, our ears are not perfect. Our ears tend to hear flat in the high register. So in order for it to be perceived as being in tune, the octaves have to be stretched bigger than the doubling of frequencies, which is mathematically perfect. Our ears are not perfect. And this is what stretch tuning is about.

So when a piano tuner tunes a piano, for example, they don't just tune perfectly because if they did it would sound out of tune, and they know how to finesse the pitch just enough to make it sound right to the human ears. There's actually even more to making a piano sound in tune than just stretch tuning, but that's a subject for another video. So remember, you can depend upon tuners only to an extent. Ultimately, you have to use your ears. That's the final judge. Thanks so much for joining me. Once again, Robert Estrin here, and
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Comments, Questions, Requests:

Fulvia * VSM MEMBER * on April 6, 2017 @5:22 pm PST
I seem to have an issue with the lower octaves after my piano get tuned, to me they sound a bit higher than they should. It that also due to my own hearing?
Robert Estrin - host, on April 7, 2017 @12:12 pm PST
Sometimes with smaller pianos, the lower notes are difficult to deal with. Short bass strings have very strong overtones which may conflict with the fundamental pitch of higher notes making them sound out of tune even if they are in tune. A good tuner has to find compromises that make pianos sound good when dealing with these issues.

Here is an article and video which discusses the overtone series:
Nigel Cockman * VSM MEMBER * on April 5, 2017 @3:07 am PST
Thanks, Robert, another of your fascinating musical insights. Keep 'em coming!!!!
Nigel (UK)
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