Historical Tuning: Rediscover the Classical Sound World
Composers like Bach and Beethoven didn’t tune their keyboard instruments to the equal tempered tuning system we use today. They used unequal temperaments, giving subtle characteristics to each key — which are completely lost in equal temperament.
VIDEO TRANSCRIPT
Ever wonder why composers chose a particular key? Does key choice even matter? In the Classica era: Absolutely, yes! Their method of keyboard tuning created harmonic colors that could evoke various moods — known as key characteristics.
So, let’s talk about historic keyboard tuning and what gets lost in the musical language of Haydn, Mozart, and Beethoven due to the equal temperament tuning system used today.
EQUAL TEMPERAMENT
What is equal temperament? It’s a tuning system where the octave is divided into 12 perfectly-equal half steps, or semitones.
One way to imagine it is as a pie. The pie represents one octave — which is then divided into 12 equal slices. As a result, only one interval — the octave — is acoustically pure. All the other intervals — 3rds, 5ths, 6ths, etc. — are slightly altered. This means that the intervallic relationships in every key are exactly the same. But, they are also equally wrong. Our ears have been conditioned to accept these slight imperfections.
Today, many musicians are taught that, historically, keyboards were tuned to play in one specific key and would have to be re-tuned to play in a different key. Then, someone came along and invented equal temperament, which allowed keyboard music to flow freely from one key to another. To celebrate this new, superior tuning method, Bach wrote his famous sets of preludes and fugues in the 24 major and minor keys [The Well-Tempered Clavier] and everyone lived happily ever after.
But… that story is not accurate.
UNEQUAL TEMPERAMENT
In German, Bach called it Das Wohltemperierte Klavier — the Well-Tempered Clavier, not the Equal-Tempered Clavier.
Let’s look a bit deeper into the meaning of that title: Well-tempered Clavier…
Bach did not use equal temperament. Neither did Haydn, Mozart, Beethoven or any of their contemporaries. They used unequal temperaments — also known as Well-tempered. In the Well-Tempered Clavier, Bach celebrated unequal tempered tuning, not today’s equal tempered tuning.
So what’s the difference?
The unequal temperament I use for my fortepiano was developed by Johann Philipp Kirnberger. It was widely used in the Baroque era and persisted through the era of Haydn, Mozart, Beethoven, and beyond.
There are many types of unequal temperaments, but this one — Kirnberger III — is built around seven acoustically-pure fifths and five fifths that are slightly narrow, giving you more acoustically pure intervals than equal temperament. This means that you play harmoniously in every key, but the intervallic relationships are not identical in every key.
This pie exaggerates a representation of intervals, but it shows that some slices are smaller than others.
So, what does this mean for the music?
KEY CHARACTERISTICS CREATED BY UNEQUAL TEMPERAMENTS
It means that some keys are more or less acoustically pure than others, giving each key a unique quality and character. This creates a vast world of harmonic colors called key characteristics.
These key characteristics were known and exploited by composers. In the 18th century, poet and composer Christian Schubart wrote descriptions that were popular for all of the major and minor keys.
Here are a few examples:
C Major: “Completely Pure. Its character is: innocence, simplicity, naïveté, children’s talk.”
C Minor: “Declaration of love and at the same time the lament of unhappy love. All languishing, longing, sighing of the love-sick soul lies in this key.”
A Major: This key includes declarations of innocent love, satisfaction with one’s state of affairs; hope of seeing one’s beloved again when parting; youthful cheerfulness and trust in God.
F-Sharp Minor: “A gloomy key: it tugs at passion as a dog biting a dress. Resentment and discontent are its language.”
Perhaps the most unstable key in this system is F-sharp minor. You have to really search to find music written in this key. All of the intervals are narrow, producing a heightened sense of tension.
If you’d like to go deeper, then I highly recommend reading Dr. Rita Steblin’s A History of Key Characteristics in the Eighteenth and Early Nineteenth Centuries.
Key choice was crucial in the Classical era. Fortepianos tuned in unequal temperaments transport you to the vast, expressive world of colors and key characteristics in which Haydn, Mozart, and Beethoven lived, a world that is lost in equal temperament.