The decision to change the standard pitch of instruments from 432Hz to 440Hz was not made by a single person or organization. It was a gradual shift that occurred over several decades and involved various factors.
The process of standardizing the pitch began in the 19th century as musicians and instrument manufacturers sought a consistent reference pitch for tuning. Prior to that, different regions and even individual musicians used different pitches, leading to inconsistencies when playing together.
One important milestone in the shift to 440Hz was the International Pitch Conference held in London in 1939. The conference aimed to establish an international standard for pitch, and while 440Hz was proposed, it did not gain widespread acceptance at that time.
However, after World War II, the 440Hz pitch gained more traction due to various factors, including technological advancements and the influence of organizations such as the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). These organizations promoted the adoption of 440Hz as the standard pitch.
The reasons behind the choice of 440Hz over 432Hz are not entirely clear and have been the subject of debate and speculation. Some proponents of 432Hz argue that it has more natural and harmonious qualities, claiming it aligns better with the vibrational frequencies found in nature and the universe. However, these claims lack scientific evidence, and the choice of 440Hz was likely driven more by practical considerations and the need for a standardized reference pitch.
It's important to note that despite the predominance of 440Hz as the standard pitch, there are still musicians and groups who prefer to use 432Hz or other alternative tunings based on personal preference, aesthetics, or spiritual beliefs. The choice of pitch can vary depending on the style of music, cultural traditions, and individual artistic choices.