432 Hz, 440 Hz: which is the right tuning?

In the world of sound therapy, people often talk about "ideal" tuning frequencies to promote harmony and well-being. The most frequently mentioned is undoubtedly 432 Hz. However, most professional musicians and luthiers tune their instruments to 440 Hz, or even 442 Hz in contemporary orchestras.

So, what is the correct tuning? Where do these different reference frequencies come from? Does a "right" and universal frequency really exist?

This article offers a historical and practical overview of the issue of musical tuning and reference pitch, tracing its empirical origins, scientific evolution, and current uses.

Tuning and Reference Pitch: Between History, Science, and Vibrational Awareness

An Empirical History of Sound

Before Heinrich Hertz’s research on frequencies (in the late 19th century), music was transmitted orally and through instrumental practice. There was no precise system to measure vibrations per second. Instruments themselves preserved the memory of pitch: flutes, ancient organs, stringed instruments – all were tuned according to the practices of their time and context.

Heinrich Hertz (1857–1894), a German physicist, was the first to measure and demonstrate the propagation of electromagnetic waves, giving his name to the unit of frequency: the Hertz (Hz). His work made it possible to associate a specific sound pitch with a measurable frequency in cycles per second, paving the way for a scientific approach to sound.

Ancient Pitches and Historical Music

Pitch has never been universal: old organs, baroque or classical instruments could vary by dozens of hertz depending on the era and location. Some medieval organs have been found tuned around 392 Hz, while others were at 465 Hz.This was not a fixed value, but a way of optimizing the natural resonance of each instrument – especially stringed ones – and avoiding excessive tension that could cause strings to break.

Today, musicians who specialize in early music use historical tunings (for example 415 Hz for the baroque period), as well as historical temperaments, which differ from modern equal temperament, to recapture the harmonic color of the time.

The 19th Century: Toward a Science of Frequency

With the development of acoustics in the 19th century, scientists attempted to standardize musical pitch. Nevertheless, tuning remained highly variable from country to country, even from city to city: instruments were tuned to around 430 Hz in Paris, 435 Hz in Milan, 450 Hz in London. Beethoven’s tuning fork, preserved in the British Library, is set to 455 Hz.There was still no international agreement, and each opera house or orchestra used its own standard.

The Standardization to 440 Hz

The progressive standardization of the 440 Hz pitch began in the 1930s, with a first recommendation made in London in 1939. It was only in 1955 that the International Organization for Standardization (ISO) officially adopted 440 Hz as a reference pitch.This standard was intended to unify musical practices globally, but in reality, it remains only a recommendation.

A Current Trend Toward Higher Pitch

Today, many orchestras tune their instruments to 442 Hz or 444 Hz, especially in Germany. This choice is often driven by a desire for greater brilliance, harmonic tension, and stronger projection in large concert halls.

The Modern Myth of 432 Hz

In sound therapy practices, 432 Hz is often presented as a "natural" frequency, linked to well-being and cosmic harmony.Although this idea lacks solid historical evidence, it has the merit of bringing attention back to frequencies, vibrations, and their role in health.

This perspective aligns with a more holistic view of medicine, which complements mechanical, pharmaceutical, or surgical approaches with energetic and sensory dimensions.

An Individual Vibrational Consciousness

As Jonathan Goldman reminds us, “We are all unique vibratory beings.”In vibroacoustics, my observations clearly show that every person has a unique sonic imprint.

I published the article “Human as a Multidimensional Harp: A Convergence between Therapeutic Music and Vibroacoustic Harp Therapy” in the proceedings of the 7th Biennial Congress of the ISQRMM (Interdisciplinary Society for Quantitative Research in Music and Medicine, 2023, USA), one of the first scientific studies on human body frequencies.Through Vibroacoustic Harp Therapy (VAHT), it is possible to observe how musical frequencies act differently on each individual, revealing a personal vibrational signature.

This uniqueness makes the idea of a universal “ideal tuning” irrelevant.True harmony is built through attentive listening, adapted to each individual.

Recommendations for Harpists

For harpists, it is essential to tune the instrument according to the luthier’s specifications. Each harp is designed to resonate best at a specific string tension. Tuning outside of this range may affect sound quality or even damage the instrument (strings becoming too tight or too loose).

Changing pitch reference may also compromise semitone accuracy, especially on lever harps. For these reasons, I recommend tuning to 440 Hz.

It is also important to carefully choose sound therapy instruments (bowls, chimes, gongs...) so that they are in harmony with your harp.

The idea that 432 Hz is the “perfect frequency” is a recent construction, widely spread since the early 2000s, often for commercial purposes in the wellness world.While it may awaken a useful interest in frequency awareness, it lacks historical and scientific grounding.

For musicians and sound therapists, the question of reference pitch is secondary.On the one hand, each human being has their own resonant frequencies, as demonstrated by vibroacoustic work.On the other hand, the human body responds to all audible frequencies: it does not only resonate at 432 or 440 Hz, but across the entire audible spectrum, depending on the situation, emotion, intention, and context.

Many other factors are far more decisive in the therapeutic impact of sound:

• the quality of timbre and the beauty of the sound,

• the rhythm, which structures attention,

• modes and harmonies, which color the emotional experience,

• the intention set in the playing,

• the temperament and tuning of intervals as relationships between notes (an upcoming article will explore historical temperaments),

• and the vibrational and sound intensity, which determines the depth of impact.
  

Thus, it is not frequency alone that heals or elevates, but the conscious relationship between the musician, the sound, and the person receiving it.

Tuning is not just a matter of numbers: it reflects our way of listening, feeling, and connecting sound to life.Its evolution – from empiricism to standardization, and now to contemporary exploration – reflects a continual search for balance and truth.

Do you want to know more about harp therapy through improvisation ? The Soul of Modal Improvisation is made for you!

Marianne Gubri