Bill, This is a very good description of setting that initial octave and a framework of thirds for the temperament. It never occured to me to also check the 6:3 on the A3 to A4 octave. This can help speed up the process and get on to setting the temperament. Sometimes I get confused listening to the third-tenth test on certain pianos and it is nice to have a back-up check. In my opinion it is easy to get that first octave too wide, which if you start with A4 and tune down an octave your F will be too flat at about 7 bps. Another double check that I like using is B1 as well as F2 for setting the A440. I guess all these years I only associated the 6:3 test with the bass. This is one of the things that keeps my interest up in this work. You just never know it all. Thanks. Always learning, Doug Hershberger, RPT ----- Original Message ----- From: <Billbrpt@aol.com> To: <pianotech@ptg.org> Sent: Friday, December 17, 1999 7:03 AM Subject: Re: Temperament Setting Question > In a message dated 12/17/99 6:11:42 AM Pacific Standard Time, > pianotoo@imap2.asu.edu (Jim Coleman, Sr.) writes: > > << Hey, for all practical purposes the 5/4 ratio works just > fine. >> > > Jerry, > > After trying all of the suggestions, especially Jim's, consider this: It > will be much easier to know that the relationship is not correct than when it > is. It is that kind of off-balance feeling just like when you have five > against four in music. But when you have the A3-A4 and the F3-F4 octaves > sounding good and your 3rds F3-A3-C#4-F4-A4 all seem to progress > proportionately, you'll have it. You'll also have the best framework for > avoiding the most common error in temperament tuning today known as the > Reverse Well error. > > When looking for the error, you will never change your A4. You could have > too wide or too narrow an octave between your A3 and A4. The usually best > recommended compromise is somewhere between a 4:2 and 6:3. Using the untuned > (as of yet) test note, F3, the 3rd, F3-A3 should beat slightly slower than > the 10th, F3-A4 (the test for a 2:4 octave), proving that it is wider than a > 4:2. > > Then, using the untuned (as of yet) test note C4, the minor 3rd A3-C4 should > beat slightly faster than the 6th, C4-A4 (the test for a 6:3 octave), proving > that it is slightly narrow of the 6:3 octave type. This is a very fine > distinction. You have to be able to discern the Rapidly Beating Intervals > (RBI) to a very fine degree. If both tests seem about right, the octave is > about right. Sometimes there is not much difference between the 4:2 and 6:3 > at this point, particularly on a low inharmonicity piano. You should be able > to hear this difference more clearly on a high inharmonicity piano such as a > Steinway. > > Once you are satisfied with your A3-A4 octave, ( it sounds more or less > "pure" when played but the RBI tests are also satisfactory), if the A3-C#4 & > C#4-F4 is inverted (faster-slower) [which would also be the rock solid > foundation for a typical Reverse Well error], it means that your F3 was too > flat, thus causing your F4 to be too flat. Try sharpening your F4 to see if > the A3-C#4-F4-A4 relationship is then satisfied. You may still have to > flatten the C#4 a little too but once you have the top of this correct, see > if you can then make an acceptable F3-F4 octave. > > As Jim pointed out, the low end of the tenor on a piano with plain wire on a > hockey stick shaped bridge will be skewed. Your 3rds will be a little slower > than expected. Your 5ths may even end up a little wide. It is very > important to the harmony of the music that will be made on the piano that you > do not have 3rds that are way out of proportion. > > This is where closely voiced chords are played. It is easy to make the piano > sound disharmonious by concentrating on favoring 4ths, 5ths and octaves and > ignoring the 3rds. Moreover, the 3rds are pretty important all the way down > to F2 but lose their importance after A3. After A3, you can let them become > faster as you stretch the octaves to get more of the "singing tones" out of > your 10ths. > > Bill Bremmer RPT > Madison, Wisconsin > > P.S. Speaking of Reverse Well, I found a particularly exaggerated example of > it yesterday on a nice Kawai KG-2D. The F#3-A#3 and Ab-C4 3rds were nearly > pure, the F3-A3 and G3-B3 3rds very fast and sure enough, the C4-E4 3rd was > the very fastest 3rd in the entire temperament. To me, all music would sound > like a nightmare on such a piano even though at standard pitch, I could still > recognize in which key the piano would be being played because of the pitch > alone. > > To me, the "color" (which I personally do not associate with the colors we > see, i.e., blue, red, green, etc.) would be completely inappropriate even > though the pitch is more or less standard. It seems to me that people are > calling two entirely different perceptions of musical tone or tonality by the > same use of jargon, namely the word, "color" and that is what is causing the > confusion about hearing "color" in ET. >
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