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It's All About the Perfect 5th! A Musicological Perspective

  • 1.  It's All About the Perfect 5th! A Musicological Perspective

    Posted 11 days ago

    IT'S ALL ABOUT THE PERFECT 5th: A Musicological Perspective 

    I am writing this little essay 'for piano tuners' but 'from the perspective of a musicologist.' Let's talk about what is actually important in music regarding the intervals we use and how we tune.

    Overall, perfect fifths are fundamental to the structure and sound of Western music, playing a key role in harmony, chord construction, tuning systems, tonal relationships, and overall musical expression.

    The intervals of the octave and the perfect fifth have remained the two most important building blocks in Western music; the octave providing the framework of stability and repetition; and the fifth, generating the primary harmonic driving force, the dominant to tonic cadence.

    The 'perfect fifth' is more consonant (consonance vs. dissonance), or stable, than any other interval except the unison and the octave. In some sense, it is even more important than the octave, which I will explain. It occurs above the root of all major (and minor) chords (triads) and their extensions. Until the late 19th century, it was often referred to by one of its Greek names, diapente. Its inversion is the perfect fourth. The octave of the fifth is the twelfth, hence, the 'Pure-12th Piano Tuning' achieves the musical goal of a 'Perfect 5th.' Violins, violas, and cellos  are tuned in 5ths. The 'Circle of 5ths' is a fundamental concept. So, it wasn't by accident that the first steps towards harmony in Western music started with the first intervals of the overtone series. The early polyphony of the middle ages consisted in one or more voice parts accompanying the cantus firmus, often in parallel motion using the interval of the octave, fifth or fourth (the first intervals found in the overtone series).    

    Harmony: Perfect fifths are considered one of the most consonant intervals in music. When two notes are played a perfect fifth apart, they sound pleasing and stable to the ear. This stability forms the foundation of harmony in Western music.

    Chord Building: Perfect fifths are essential for building chords. In traditional Western music theory, chords are often constructed by stacking notes in intervals of a third (major or minor). The perfect fifth is a common interval found in many chords, such as the power chord (used in rock music) and the perfect fifth interval itself forms the basis of the dominant triad in tonal music.

    Tuning Systems: Perfect fifths are crucial in tuning systems. In the context of equal temperament tuning (the tuning system commonly used in Western music), the perfect fifth is the interval that is tempered or adjusted to allow all keys to be played equally well. This compromise is necessary to ensure that music can be played in all keys without sounding out of tune.

    Functional Harmony: In tonal music, the perfect fifth plays a significant role in establishing tonal centers and creating harmonic tension and resolution. For example, the perfect fifth relationship between the tonic and dominant is fundamental in establishing tonality and creating a sense of resolution when moving from the dominant back to the tonic.

    Melodic and Harmonic Context: Perfect fifths are prevalent in melodies and harmonies across various musical genres. They provide a sense of stability, direction, and resolution, contributing to the overall structure and coherence of musical compositions.

    On a personal note, in my early years as an orchestral trombonist, it was obvious that an important role of the trombone section included providing underlying support chords. Three trombones can provide a triad chord. The section member who had the 5th had to be 'perfect', even more so than the member who had the 3rd, since half the literature is in a minor key.

    Now, let's look at the math. An octave-based equal temperament puts the 5th  at 

    2^(7/12) = 1.4983, 

    where the perfect 5th is 1.5. 

    Therefore, the 5th nearly 2 ¢ flat, since 

    1200*log2(1.4983 / 1.5) = -1.955 ¢.

    Now let's examine the 5th using the 'Pure 12th System'

    3^(7/19) = 1.4989

    1200*log2(1.4989 / 1.5) = -1.2347 ¢ 

    Therefore, 1.955 – 1.2347  = 0.7203 ¢, or in other words, the Pure 12th System produced a 5th that is ¾ ¢ better to being a perfect 5th. But, more importantly, it produces an absolutely Perfect 12th, therefore, the 5th above the octave IS A PERFECT 5th!

    Now ask yourself, why would a piano tuner, from a musicological perspective, want to even consider tuning using 3rds, 10ths, 17ths and counting beats from these 3rds? Yes, historically, it is easier to 'count beats' of progressive 3rds, but we now have 'new technology' that eliminates the need for this. The musicologist is telling us about the fundamental importance of the Perfect 5th! We now can achieve it with the 12th if we use new technology.

    Steven Norsworthy

    May 8, 2024

    http://rf2bits.com/

    http://PianoSens.com

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    Steven Norsworthy
    Cardiff By The Sea CA

    steven@rf2bits.com
    (619) 964-0101
    ------------------------------



  • 2.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 10 days ago
    Steven - sorry to potentially upset you but one can't look at fifths whilst ignoring thirds. Perfect 5ths result in Pythagorean tuning and the prevalence of this caused Meantone tuning to hold sway when thirds became harmonically important.

    Both Meantone and Pythagorean have their place but music and tuning have moved on a little since then on keyboard instrument and the 18th and 19th centuries were all about finding compromises which perfect fifths don't allow. 

    Ron Koval's temperament demonstrates helpful pragmatism and it would be great if perhaps you might be able to try it and see what a perfect 12th methodology of extending it throughout the instrument might result in.

    Best wishes 

    David P 

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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 1342 850594





  • 3.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 10 days ago

    I stand "Cantus Firmus"



    ------------------------------
    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
    ------------------------------



  • 4.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 10 days ago

    Question: Why would a piano tuner, from a musicological perspective, consider using thirds, tenths, and seventeenths, given the fundamental importance of the Perfect 5th to tune a piano? 

    Answer: The use of interval comparisons using thirds, tenths, seventeenths, and, in particular, minor thirds can be used to accurately measure and adjust the temper of octaves and fifths. They allow one to form and execute a tuning strategy that produces the best musical result for each piano they tune. 



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    Rick Butler RPT
    The Butler School of Piano Technology
    Bowie MD
    240 396 7480
    RickRickRickRickRick
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  • 5.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 10 days ago

    Another (but not necessarily the smartest, best,  or most authoritative) answer is: On a well scaled (and generally reasonably large) instrument...no argument whatsoever from an ET perspective. However,  on a PSO (of which there are MANY in existence and often comprise a high % of the typical piano tuner's clientele ownership and thus a proportionately higher % of exposure to requiring 'best compromise' theory and practice for optimal musical usage) it simply doesn't always "work as advertised". Therefore we need other "tools" at our disposal to effect a reasonably acceptable result. 

    Additionally, in the case of PSO's that are used almost universally for beginners or "elementary" playing, there exist highly satisfactory compromises that will enhance the musicality of the most used key signatures at the expense of the least (or never) used key signatures, and if mutually agreed upon can produce a superior result under such limited playing capacity. 

    Each temperament scheme has its place and since piano tuners are the ones doing it (in most cases) it's up to us to determine (in consultation with whoever is playing (and/or paying) what is the best application under the circumstances. 

    Others may disagree... 🤔 

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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  • 6.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 10 days ago

    Peter, from what I can gather, you will need 'not just any app', but an app that has accurate full IH (some do and some don't) in addition to an accurate tuning curve generation for Pure 12th. Given those conditions, the result will be fine on any scale piano. I'd recommend a consultation with a Pure-12th expert who has evaluated the apps that provide this. I think we both know someone who can opine privately on this from experience! --- Steve N.



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    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
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  • 7.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 4 days ago

    Colleagues, in compliance with Patrick's request, and then seeing thereafter extremely repetitive long replies from one in particular that were an afront after Patrick made the polite request on the rules, I marked those particular long replies that were off-topic as inappropriate. For those who made comments after, I enjoyed reading your on-topic replies and invite you to repost them. If we keep venturing into UT, I request those interested in UT to start a whole new thread on that subject. Let's keep the subject on the original subject matter. Kindly, and professionally, Steve. 



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    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
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  • 8.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 4 days ago

    I am a little confused why my critique of the OP was removed, presumably marked "inappropriate." It was a direct reply to the content of the OP from a musicological perspective. I would like to repost since it was in fact on topic.

    ___________

    Steven,

    Thank you for sharing this perspective. I agree that the fifth is incredibly important for many of the reasons you state, but I would disagree with your conclusion that tuners should tune P12 for the reasons you gave. This is not to say that I don't think there is value in P12 tuning and if you or others like it, by all means use it. 

    Certainly, parallel organum of the Middle Ages utilizes the P5, but during the Middle Ages the M3 was considered dissonant. In Pythagorean tuning, M3s are 22% wide from perfect if memory serves. In ET they are around 14%. As music developed in western society, 3rds became a function of consonance in music in contrast to earlier times. Tempering at least some 5ths not only allowed avoiding the wolf but also allowed for more pleasing (slower beating) 3rds. 

    If there is any doubt about the importance of 3rds in western music, consider the 5ths that were compromised almost universally in well and Victorian temperaments, following the circle of fifths: C-G, G-D, D-A, A-E. This was very intentional, since this sequence placed E closer to C which allows the M3 to beat more slowly, in some cases making a nearly P3. Well temperaments usually prioritize nearly P3rds in the keys closer to C in the circle of 5ths, such as G and F, all of which keys were considered the most consonant, not because of P5s but because of the 3rds. 3rds were in fact foundational to western music as we know it, and the most consonant keys had the most tempered fifths.

    The statement "perfect 5ths are essential for building chords" is not correct. While 5ths are essential, P5s are not as I have demonstrated above. Even the relatively rapidly beating G-D in Kirnberger III is partially masked by the 3rd in a G major triad.

    In functional harmony, it is correct to see significance in the Tonic/Dominant (I/V) relationship, but again this is not a necessarily a P5 relationship. Further, it is not so much the fifth comprising the root of the dominant chord that creates tension, but the tritone which is created from the 5th and 7th partials of the dominant root. This translates primarily to the 3rd and 7th (i.e. 3rd from the root and a 3rd from the 5th) of the chord being the primarily creators of tension that "want" to resolve back to the tonic (I).

    For these reasons, I do not recommend P12 tuning universally, especially for classical music. P12 tuning by necessity makes faster beating 3rds which I believe I have given a sufficient argument as to their historic importance in the development of western music. Functional harmony depends on 5ths for certain, but the P5s as you stated in the OP are not necessary for functional harmony at all. Since they are not necessary for functional harmony, P12 tuning is not necessarily the best tuning for western music.



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    Tim Foster RPT
    New Oxford PA
    (470) 231-6074
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  • 9.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 4 days ago

    Tim,

    Thanks for reposting, as yours was simply taken down by the 'system' when it was following one that was taken down for not being on point.

    That being said, I encourage you to post all UT preference opinions on the new thread by S. Rosenthal, which he humorously and appropriately entitled "A Tempermental Journey." This is a great new place for the UT guys, since it is a very small minority who want UT on a modern concert grand piano. To each his own.

    There is room at the table for all here! I respect that, but also adhere to the 150-year-old tradition of the move toward atonality that Liszt and Wagner started and matured around the turn of 1900 with the New Viennese School of composers. The German tuners had, by historic accounts, already embraced ET by 1850 and some say the English tuners even before that. I love the sound of Rubinstein, Horowitz, Bronfman, Argerich, Hamlin, and all the 'greats' of prior and recent who play the full range of literature on great-sounding ET tunings on fabulous Steinway D's. So, ET is here to stay, and I don't see serious pianists turning back the clock to pre-1850. 

    On a personal 'note', my Fazioli sounds to the ears of everyone who has been in the room, 'the best sounding tuning they have ever heard' and that came from 4 tuners each with over 35 years of high-level tuning history. It simply came from Pure12th being spot on using the 'new technology'. I can play literature from Bach to Bartok and it all comes off well. Everything is unbiased and consonant sounding. It sounds 'mainstream.'

    Respectfully, 

    Steve N.



    ------------------------------
    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
    ------------------------------



  • 10.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 3 days ago
    Steven - the problem is that whilst ET is a compromise that hasn't been _very_ bad for over 100 years leading to de facto adoption, what you propose and with self professed "Musicological" authority and therefore with academic implication, is that only perfect 5ths are required for harmony and that therefore P12 stretching is proper and acceptable and leading to near Pythagorean major thirds which are not acceptable and especially when there aren't softer thirds to relieve them in the tuning system. This is plainly wrong.

    Any good ideas should be capable of peer review and withstand debate. 

    The whole purpose of enjoining in discussion in a forum is for debate to bring in other ideas and to move a perspective forward and progress both learning and understanding. 

    That the universal presence of Pythagorean thirds is unacceptable led naturally to the suggestion that UT could overcome the disadvantage. 

    Instead you require anyone who calls you out on mistaken assertions, whether that 
    - Prokofiev requires Equal Temperament to be used, or that 
    - only 5ths are required for harmony, or 
    - that Pythagorean 3rds throughout the key spectrum are acceptable without relief of smoother thirds,
    you expect to go away elsewhere and leave your self-professed and mistaken authority unchallenged.

    That it should be unchallenged and unchallengeable is unprofessional as well as misleading to those new to understanding of tuning and who should not be misled.

    As this is a professional forum from which people new to piano tuning subjects can expect reliable information, it is professionally inappropriate for a thread of professional standing purporting "Musicological" authority not to contain contributions from people with other professional and academic experience.

    Rather than obstinately holding to foundations which do not bear scrutiny and complaining about anyone who says so, perhaps you might profit from the development of the thread as it was before you required any relevant suggestions to be deleted, finding a new and expanded usefulness for your commercial device in the directions which have been indicated. Working together with Ron Koval could be particularly productive as his tuning requires ETD assistance and therefore gives a place for your technology. P12 ET tuning is not the only context from which you can profit.  

    Best wishes

    David P




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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 1342 850594





  • 11.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 3 days ago
    Tim Foster wrote:

    "...I do not recommend P12 tuning universally, especially for classical music. P12 tuning by necessity makes faster beating 3rds which I believe I have given a sufficient argument as to their historic importance in the development of western music. Functional harmony depends on 5ths for certain, but the P5s as you stated in the OP are not necessary for functional harmony at all. Since they are not necessary for functional harmony, P12 tuning is not necessarily the best tuning for western music."

    Briefly:

    Tim cites the Pythagorean M3rd as 22 cents wide, and the pure octave ET M3rd as 14 cents wide. These are rounded figures. Please note that the pure 12th ET M3rd _also_ rounds to 14 cents wide.(!) Where are these wide M3rds of pure 12th ET so often complained about? They don't actually exist! To be a bit more precise, Pythagorean M3rds are 21.5 cents expanded. Pure octave ET M3rds are 13.69 cents expanded, and Pure 12th ET M3rds are 14.1 cents expanded. The difference between pure octave ET M3rds and Pure 12th ET M3rds (0.41 cents) are actually within the practical tolerances of many piano tunings and thus differences between the two are actually almost non-existent. Pure 12th ET M3rds are not significantly wider than pure octave ET M3rds! Repeating, within reasonable tolerances of real tunings, pure 12th ET M3rds are _not_ significantly wider than pure octave ET M3rds.

    And,

    I wish to point out the ambiguity inherent in using the expression "P5" or "P12" to indicate pure, untempered intervals. In music theory "P5" signifies "perfect 5th", that is, 7 half steps as opposed to the 6 half-steps of a diminished 5th or 8 half steps of an augmented 5th. Really, if you mean to discuss pure 5th (or pure 12th), then use the term "pure" (or just, or untempered) rather than P5 (or P12) which many people read as "perfect 5th" (or perfect 12th).







  • 12.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 3 days ago

    Kent,

    In music theory, a perfect fifth is the musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, or very nearly so. In classical music from Western culture, a fifth is the interval from the first to the last of the first five consecutive notes in a diatonic scale. Wikipedia

    I intentionally wrote the article from the perspective of a professional musician who grew up in that culture.

    I knew in advance I would catch flack from the piano tuners. So be it.

    Best,

    Steve



    ------------------------------
    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
    ------------------------------



  • 13.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 3 days ago
    Actually, the Oxford dictionary of music says,

    “The somewhat hollow-sounding 4th, 5th, and octave of the scale are all called Perfect. They possess what we may perhaps call a ‘purity’ distinguishing them from other intervals … [I]f Perfect or Minor interval [is] reduced [by a semitone] it becomes Diminished; if any Perfect or Major interval be increased by a semitone it becomes Augmented.

    So, there you have it, the definition involves scale degrees not tuning; there is a vague reference to “purity”, but no specific reference to tuning, such as "tuned untempered".

    So, I believe my point that the term “Perfect” is an at-least ambiguous and probably poor synonym for “pure” is confirmed.




  • 14.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 3 days ago

    Wikipedia: The term perfect has also been used as a synonym of just, to distinguish intervals tuned to ratios of small integers from those that are "tempered" or "imperfect" in various other tuning systems, such as equal temperament.[5][6] The perfect unison has a pitch ratio 1:1, the perfect octave 2:1, the perfect fourth 4:3, and the perfect fifth 3:2.

    Look at the references at the bottom. All highly credentialed music theorists and musicologists. That is the culture I grew up in as a music student in the conservatories and in the orchestras. 

    Steve N.



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    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
    ------------------------------



  • 15.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Member
    Posted 3 days ago

    While it is true that in music theory, a perfect fifth is the musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, this definition is not sufficient for pianos because having a fundamental frequency ratio of 3:2 does not guarantee a beatless fifth, which is the way a listener recognizes a perfect interval.  The only reason the precise mathematical ratio has any significance to the human ear is that harmonics are exact whole-number multiples of the fundamental.  In a perfect fifth the 3rd harmonic of the lower note and the 2nd harmonic of the upper note are identical in frequency and therefore will be beatless.  But pianos do not have harmonics.  They have partials that are slightly sharp from what the harmonic would be.  Therefore a perfect fifth on a piano (the one that would sound beatless) would require that the fundamental have a ratio that is slightly more than 3:2.  But it gets even more complicated when we consider that a fifth has other coincident partials besides 3:2, such as 6:4 and 9:6.  And unlike instruments like wind instruments with pure harmonics, the 6:4 perfect fifth will not occur at the same tuning as the perfect 3:2 perfect fifth.  Therefore there are several different kinds of "perfect fifths" on a piano, and we need to specify which one we mean.  I suspect that if you tuned C1/G1 for a perfect fifth would be listening for the 6:4 fifth, but when tuning C5/G5 as a perfect fifth you would be listening for the 3:2 fifth because that would be the most prominent coincident partials.  For instruments without inharmonicity, the 3:2, 6:4, 9:6, etc. would all be perfect at the same time. 



    ------------------------------
    Robert Scott
    Real-Time Specialties (TuneLab)
    fixthatpiano@yahoo.com
    Hopkins MN
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  • 16.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 3 days ago

    Robert,

    All wind and brass instruments have inharmonicity in their natural 'positions'. For example, the exponential shape of a brass instrument bell is a mathematical approximation to put the overtone series as close as possible to harmonic integers but it is still 'imperfect' and the instrumentalist has to make on-the-fly adjustments of embouchure to compensate. Of course the pianist cannot make those adjustments during a performance. Steven Rosenthal's post of the Debussy Clair de Lune is very revealing. The human listener has 'adapted' to ET on the piano as a compromise to the full range of keys and repertoire. Does anyone think the example of Evgeny Kissin's Clair de Lune is anything other than 'aesthetically lovely?' You can bet his Hamburg D was tuned with ET of some sort. 

    You missed my point that the 12th or 3rd overtone IS PERFECT with Pure12th. That is a very common interval for spread chords on a piano. So, 'no', the 5th (3:2) is not Pure/Perfect but close (-1.23¢) but the 3:1 is Pure/Perfect with proper Pure12th ET using the best new tech app and device.

    Steve N.



    ------------------------------
    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
    ------------------------------



  • 17.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 3 days ago
    So if your 12ths are perfectly mathematically pure, we come back to how they stack up to result in major thirds which are not Pythagorean?

    If the Debussy Claire de Lune is the test piece then https://www.youtube.com/watch?v=NXVShKy0LP4 
    is appropriate to include in the mix. In Db major this recording is one in which the fifths are pure as you recommend and the Db F major third 21.5 cents wide so this recording should meet your criteria of sounding good.

    Best wishes

    David P
    --
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    David Pinnegar, B.Sc., A.R.C.S.
    antespam@gmail.com
    - - - - - - - - - - - - - - - - - - - - - - - -
    +44 1342 850594





  • 18.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Member
    Posted 3 days ago

    Steve, you are right about the natural resonant frequencies of a wind instrument being inharmonic.  But I was referring to the overtones of a single note.  In a wind instrument those overtones will be locked together.  The waveform of a wind instrument is periodic.  Every periodic waveform of frequency F can be decomposed into a series of sine waves of frequencies nF for n = 1,2,3....  In other words, harmonics.  The waveform of a piano note cannot be represented in this manner because the waveform is not periodic.

    As for which intervals are perfect, any interval can be made perfect by a corresponding tuning.  You can have a perfect 3:2 fifth tuning, a perfect 6:2 twelfth tuning, or a perfect 4:2 octave tuning, etc.  As for which of these tunings sound the best, that is entirely another matter and not one I am qualified to comment on.  I will leave it up to musicologists like you to decide that.                      



    ------------------------------
    Robert Scott
    Real-Time Specialties (TuneLab)
    fixthatpiano@yahoo.com
    Hopkins MN
    ------------------------------



  • 19.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 2 days ago
    Robert - yes you're perfectly on pitch in your observation and concerning brass instruments. I think that Steven's idea is how the sound of a group of instruments, as a group of strings, holds together. 

    However, in ensemble a brass group is perfectly harmonic despite inaccuracies of individual instruments' harmonics as players "lip" the note in tune with those around and a result is that major thirds in brass ensembles tend to the perfect harmonic major third and especially where horns in F are played where the fingering in the C scale is c0 d1 e0 f1 g0 rather than c0 d101 e12 f1 g0  based on pure just harmonics rather than being so dependant upon tuning with the slides. The comparison of the piano tuning with the tuning of a brass ensemble therefore doesn't work and whilst not conscious of such a brass player will be familiar with chord shapes that vary through a range of intonations. 

    Best wishes

    David P

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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 1342 850594





  • 20.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 3 days ago
    Kent - thanks so much for your clarification and I apologise for my part in contributing to confusion that has occurred.

    The musical examples posted did appear to have rather grating thirds, and seemingly moreso than standard P8 ET

    It's rather difficult to get one's head around the concept of all 12ths being pure which would seem to imply perfect fifths which when stacked would lead to Pythagorean proportions between notes and perhaps therefore my ignorance in this domain might be forgivable.

    With inharmonicity, however, the practice of P12 tuning would apparently stretch an octave and 5th more than a standard octave and equal temperament fifth. If all intervals are stretched proportionally it might not seem unreasonable for major thirds to be stretched wider than that to which we are accustomed to in standard equal tuning and audibly so. Perhaps others might share such confusions.

    When I did a spreadsheet analysis of an equal temperament manifestation of a P12 methodology, I came out with for instance a treble C at 1047.4Hz and the E above at 1320Hz vs a P12 expansion of ET at 1046.5Hz and 1318.5, so wider and by the time inharmonicity has taken its toll the real world expansion would be more. Perhaps I might not have developed the P12 expansion of the temperament so these calculations might need revision but the figures do seem to bear out the perceived greater grating of the thirds in the recorded examples.

    What also becomes interesting is the difference frequency when the 3rd is played - 272 in P8 and 272.5 in P12 vs the harmonic root C around 261.5. Of course I can be accused of an OCD obsession in looking at these difference frequencies but certainly on an organ at a console with pipes above one can hear them and they become part of the piano sound also even if we can't hear them other than in the transient. The difference note is 1/4 tone sharp with C# at around 277 and the larger the stretch the more discordant the result.

    Best wishes

    David P
    --
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    David Pinnegar, B.Sc., A.R.C.S.
    antespam@gmail.com
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    +44 1342 850594





  • 21.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 3 days ago
    David wrote:

    "It's rather difficult to get one's head around the concept of all 12ths being pure which would seem to imply perfect fifths which when stacked would lead to Pythagorean proportions between notes and perhaps therefore my ignorance in this domain might be forgivable."

    In pure 12th ET everything is stretched out like an accordion bellows. The 12th is pure which is 1.96 cents wider than in pure octave ET, the octave is tempered wide by 1.23 cents instead of being nominally pure. The fifth, already a slow beating interval, is tempered by 1.23 cents narrow, which is .73 cents wider than in pure octave ET, which is a significant amount that can be heard. The fourths, instead of 1.96 cents wide, are tempered 2.47 cents wide, which doesn't seem to bother anybody, the M3rds are 0.41 cents wider than in pure octave ET as already mentioned, a negligible difference compared to pure octave ET.

    The point of pure 12th ET is to establish a consistent stretch throughout the scale. Piano tuners have always stretched; Pure 12th ET simply attempts to codify and help regulate what has always been done in practice.

    I have on anecdote to share about pure 12th ET:

    One of the profs at the university was tired of the over-stretched tunings that he was getting on his home piano, so when he needed a tuning for his studio pianos, he specifically requested an "unstretched" tuning. I told the contract tech of the request, but, knowing that the contractor's tunings are indistinguishable from my own, I told him to do our standard pure 12th ET as usual. He did so, and the prof raved - said the tuning was the best ever, and thanked us for not stretching! The point being, pure 12th ET, when properly executed delivers a wonderfully clean, consonant sound.

    Sorry, I have exceeded my bandwidth for the day!





  • 22.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 2 days ago

    Kent writes: 

    >>Tim cites the Pythagorean M3rd as 22 cents wide, and the pure octave ET M3rd as 14 cents wide. These are rounded figures. Please note that the pure 12th ET M3rd _also_ rounds to 14 cents wide.(!) Where are these wide M3rds of pure 12th ET so often complained about? They don't actually exist! To be a bit more precise, Pythagorean M3rds are 21.5 cents expanded.<< 

        Actually, the Pythagorean comma is 23.4 cents wide.   The 21.5 cents being referenced is the Syntonic comma.  These are arrived at by different means, and the syntonic comma is the near-universally accepted limit for a M3 in the WT's. I also submit that the word "Pure" in tempering discussions is best used to describe an untempered interval.  

    Regards,  



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    Ed Foote RPT
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  • 23.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 2 days ago
    Sorry for the bobble. Thanks for the correction.

    Sent from my iPhone




  • 24.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 2 days ago
    Well, wait. The reference was to the Pythagorean major third; that is indeed 21.51 cents, right?




  • 25.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 2 days ago
    >>Well, wait. The reference was to the Pythagorean major third; that is indeed 21.51 cents, right?

    Ah,  the Pyth. M3,  yes,  it is 407 cents wide, so indeed,  it is that 21.5 cents.  The comma is 24 so that was my oversight.  

       (either eyes or memory does lapse at this age...)_

    Ed





  • 26.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 2 days ago

    Kent, thanks for the info about P12 3rds compared with P8 3rds, I didn't realize how close they were in reality. I think it shows that P12 tuning falls quite short of pure 5ths and probably in most cases short of pure 12ths.

    Question: how close does P12 tuning get to pure 12ths on an "average" piano? I'm sure mathematical limits are placed on the octave stretch.



    ------------------------------
    Tim Foster RPT
    New Oxford PA
    (470) 231-6074
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  • 27.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Registered Piano Technician
    Posted 2 days ago
    Tim Foster wrote:

    "I think it shows that P12 tuning falls quite short of pure 5ths
    "

    Correct. Sort of. The perfect 5ths in pure12 ET are theoretically tempered narrow by 1.23 cents compared with 1.96 cents narrow in pure octave ET. I consider that 0.73 cents difference to be significant. So, 5ths are cleaner in pure12 than in pure octave; they are not completely "pure" but can often sound "clean", that is, almost beatless.

    "and probably in most cases short of pure 12ths."

    A well-executed pure12 ET will have as close to a beatless 12th as the competing pairs of coincident partials (3:1, 6:2, 9:3) will allow.

    "Question: how close does P12 tuning get to pure 12ths on an "average" piano? I'm sure mathematical limits are placed on the octave stretch."

    Beatless pure 12ths tend to be a starting point in this tuning, so even "average" pianos will come quite close to the theoretical beatless target. Theoretically, the octave is tempered wide by 1.23 cents.







  • 28.  RE: It's All About the Perfect 5th! A Musicological Perspective

    Posted 2 days ago

    Let's look at the partial relationships to 'accomplish this' in the context of the partial drifting of the piano.

    The 'Pure 12' is 'pure' when the 3rd partial of the lower note has the exact same frequency as the fundamental of the upper note that is 12 whole- or 19 half-steps above the lower note. This is independent of inharmonicity (IH), of course. For example, when the fundamental of the lower note is A4 = 440 Hz, and the 3rdpartial is 3 * 440 + a little higher due to IH, say, 1320 + 3 = 1323 Hz, then the tuner will tune the fundamental of the upper note, in this case E6, to 1323 Hz, so there is 'perfect' alignment. If the machine is accurate at the timeframe window selected for this alignment, then the tuning is 'perfect' in that timeframe window. 

    I say this because the piano is a 'non-stationary' device, that is to say, the pitch of all the partials drift and are never in a steady state. We should all tune preferably on the attack phase where the power of the sound is highest before it decays, as we know for a fact from psycho-acoustic studies that we hear the best at the highest power level, and waiting for many seconds to do that 'alignment' will result in mis-alignment due to the different drift rates of the notes and their partials.

    For this reason, the best implementation of the 'Pure 12' technique should be done with a 'machine' and not by 'human aural ear.' That 'machine' should implement the STFT, or Short-Time Fourier Transform, the most robust technique for non-stationary waveforms, developed for speech, video, and music coding, dating back in the day of the 1970's at Bell Labs and MIT. To this day, a few of the newest tuning apps implement something like this, whereas the older tuning apps using zero-crossings or phase rate. The problem with these older techniques is that they do not do well with non-stationary waveforms that have multiple partials and drifting behavior. No qualified engineer would start a new tuning app project without the STFT and certainly not use aforementioned older methods. 

    The problem doing any of this with the aural human ear comes down to our inability to do this kind of high precision calculations in our brain. It is simply impossible. That is why we need machines and devices to pull it off.

    Steven Norsworthy

    Signal Processing Professional Engineer and Pianist



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    Steven Norsworthy
    PianoSens
    Cardiff By The Sea CA
    (619) 964-0101
    ------------------------------