This site introduces unknown Emanuel Bach (C. P. E. Bach).
Johann Sebastian Bachʼs *Das Wohltemperierte Klavier* has traditionally been translated into Japanese as 「平均律クラヴィーア曲集」 (*Heikinritsu Kuraviā Kyokushū*, meaning *The Well-Tempered Clavier*). However, since equal temperament (*Heikinritsu*) was hardly used during Bachʼs time, I consider this a clear mistranslation. Therefore, following Genzo Takehisa, I will refer to it as 「適正律クラヴィーア曲集」 (*Tekiseiritsu Kuraviā Kyokushū*, meaning *The Properly Tempered Clavier*). If no specific instruction is given, ChatGPT4o typically translates it as *The Well-Tempered Clavier*, but here it has been replaced with *The Properly Tempered Clavier*.
ChatGPT4o was asked: "Was the collection commonly known in Japanese as *The Well-Tempered Clavier* actually performed in equal temperament at the time? Wasnʼt the tuning system back then different from equal temperament?"
Although *Das Wohltemperierte Klavier* is translated into Japanese as *The Well-Tempered Clavier*, the tuning system used during Bachʼs time was different from the modern 12-tone equal temperament. Various tuning systems (*Stimmungen*) were in use, and the fully developed equal temperament was not yet common.
Bach likely intended the use of tuning systems corresponding to "temperaments" or "well-tuned systems" rather than modern equal temperament. These tuning systems maintained harmony across various keys while preserving the distinct character and color of each key.
Some major tuning systems of the time included:
The term *wohltemperiert* (*well-tempered*) refers to a tuning system that enables the use of all 24 major and minor keys without bias. While similar in concept to modern equal temperament, it is not identical. In Bachʼs time, subtle tonal differences between keys added color to the music.
*The Well-Tempered Clavier* was composed based on a "well-tempered" tuning system rather than modern equal temperament. This tuning preserved the characteristics of each key, enabling exploration of all keys without losing their individuality. Bachʼs goal was to create keyboard music playable in all keys using a tuning system different from todayʼs equal temperament.
ChatGPT4o was asked: "Why is it called *The Well-Tempered Clavier* in English, but in Japanese, it is called *The Equal-Tempered Clavier*?"
The term "equal temperament" was established in the 19th century to describe the 12-tone equal temperament system. In Japan, this term spread after Western music theory was introduced during the Meiji era. When Western music theory and classical music materials were translated, *Well-Tempered* was commonly translated as *Equal Temperament* because it was thought to closely resemble modern equal temperament.
The original German title, *Das wohltemperierte Klavier*, directly translates to "The Well-Tuned Clavier." The term *wohltemperiert* carried nuances specific to Bachʼs era. However, as music theory developed in the 19th century, the idea of a "balanced tuning system" was interpreted similarly to equal temperament. As a result, the Japanese term *平均律* (*Equal Temperament*) was used to describe this concept.
The name *The Equal-Tempered Clavier* in Japan became widespread partly due to the misunderstanding that Bach used modern equal temperament. Although Bachʼs "well-tuned" system differed from modern equal temperament, the term *Equal Temperament* became firmly established once it spread.
The term *Equal Temperament Clavier* was also convenient for explaining music theory in Japan. Since 12-tone equal temperament is the standard in modern music education, the subtle differences of Bachʼs tuning system were often overlooked, leading to the widespread use of the term *Equal Temperament*.
The reason why *The Well-Tempered Clavier* is called *The Equal-Tempered Clavier* in Japanese stems from the standardization of 12-tone equal temperament in 19th-century music theory and how it was translated when introduced to Japan. Although Bachʼs tuning system differed from modern equal temperament, this nuance was omitted, and the term became widely accepted in Japan.
ChatGPT4o was asked: "How is *The Well-Tempered Clavier* tuned when performed on historical instruments today?"
When performed on historical instruments, *The Well-Tempered Clavier* is typically not tuned in modern equal temperament but in historical temperaments such as *well temperament* or other classical tuning systems. These tunings highlight the tonal characteristics of each key, closer to the musical sensibilities of Bachʼs era.
This system reflects what Bach intended with the term *well-tempered*, allowing performance in all keys while preserving each keyʼs distinctive character.
Developed by Andreas Werckmeister, this system was widely used during Bachʼs time. It balances playability across keys while emphasizing specific key characters.
Designed by Bach’s student Johann Philipp Kirnberger, it adapts older systems for greater key flexibility, showcasing Bachʼs music with natural resonance.
Proposed by Francesco Vallotti, this 18th-century system slightly evens intervals between keys for flexible tuning and smooth transitions.
Performances of *The Well-Tempered Clavier* on historical instruments often use Werckmeister, Kirnberger, or other well-tempered tunings. These temperaments draw out the beauty and characteristics of each key, offering a richer sound distinct from modern equal temperament.