Solfeggio frequencies: all nine tones, explained and playable

What are solfeggio frequencies

Solfeggio frequencies are a set of nine tones used in sound therapy and meditation music. Each tone is a single pitch measured in hertz, the number of vibrations per second: a 528 Hz tone vibrates 528 times a second.

Every tone has a name and a purpose in the tradition. 396 Hz is used for releasing fear, 528 Hz is called the love frequency, 963 Hz is linked with the crown and a sense of oneness. People listen to them as pure tones, as music tuned to the tone, or as the sound of a tuning fork.

The word itself is older than the numbers. Solfeggio, or solfège, is the method of naming the steps of a scale with syllables, the familiar Do, Re, Mi. It is still taught in every music school.

Solfeggio frequencies list and chart

The chart shows all nine tones: the name each has in the tradition, what practitioners use it for, the chakra it is assigned to, and the nearest note of a piano tuned to A = 440 Hz.

Each tone has its own page with the details: how it sounds, what it is combined with, and what is known about it.

Where solfeggio frequencies come from

The story has two parts, a thousand years apart, and most descriptions mix them up.

The first part is medieval. In the 11th century the Italian Benedictine monk Guido of Arezzo taught singers with the help of a Latin hymn to Saint John the Baptist, “Ut queant laxis”. Each line of the hymn began one step higher than the line before, and the first syllables of the lines, Ut, Re, Mi, Fa, Sol, La, became the names of the steps. Later Ut turned into Do and a seventh syllable was added.

That system named the steps of a scale. It did not fix them to frequencies, and it could not: the measuring of pitch in vibrations per second came centuries later, and the standard A = 440 Hz was agreed internationally only in 1939.

The second part is modern. In the 1970s the American naturopath Joseph Puleo reduced the verse numbers of chapter 7 of the biblical Book of Numbers with the Pythagorean method, adding the digits of a number until one digit remains, and arrived at six numbers: 396, 417, 528, 639, 741 and 852. He linked them to the six syllables of the hymn. The numbers were published in 1999 in the book “Healing Codes for the Biological Apocalypse” by Leonard Horowitz and Joseph Puleo. The tones 174, 285 and 963 Hz were added later by other authors.

So both things people say are true. The syllables are about a thousand years old. The frequencies in hertz are about fifty.

The 3, 6, 9 pattern in the numbers

The nine numbers are tied together by arithmetic, and this is a large part of their appeal.

• The digits of every number add up to 3, 6 or 9: 1 + 7 + 4 = 12 and 1 + 2 = 3; 5 + 2 + 8 = 15 and 1 + 5 = 6; 9 + 6 + 3 = 18 and 1 + 8 = 9.
• The numbers fall into three groups made of the same digits in a different order: 174, 417 and 741; 285, 528 and 852; 396, 639 and 963.
• Most neighbours are 111 apart: 174, 285, 396, then 417, 528, 639, then 741, 852, 963. Only two steps break the pattern: 396 to 417 is 21, and 639 to 741 is 102.

These patterns follow from the way the numbers were built, by digit sums. They describe the numbers, not the sound: the ear does not hear a digit sum.

Solfeggio frequencies and the musical scale

Musicians often ask which notes the tones are. The answer is that they fall between the keys of a piano, some closer, some further.

741 Hz is practically the note F♯5, only 2 cents higher; a cent is a hundredth of a semitone. 174 Hz is 6 cents below F3. 285 Hz and 639 Hz lie almost exactly between two keys, so no instrument in standard tuning can play them.

Two of the tones have a real place in music. 396 Hz and 528 Hz are the notes G4 and C5 of the natural, just-intonation scale of C major built on C = 264 Hz, the scale in which A is exactly 440 Hz. Their ratio is 3 to 4, a perfect fourth, which is why these two tones sound good together.

The nine tones do not form a scale in the musical sense, because the steps between them are unequal. Music “in 528 Hz” is music tuned so that one of its notes falls on 528 Hz; for that, the note A is set to 444 Hz instead of 440.

Solfeggio frequencies and science: what has been tested

Only one of the nine tones has been tested in people, 528 Hz. In a Japanese study nine healthy adults listened for five minutes to soothing piano music tuned to 528 Hz and, on another day, to the same kind of music tuned to 440 Hz. After the 528 Hz music the stress hormone cortisol in saliva fell significantly, oxytocin rose, and the scores of tension and anxiety went down. After the 440 Hz music none of these changes was significant.

In a randomised trial in India 60 patients with high blood pressure were followed for a month. Those who listened every day to a recording of OM chanting composed at 528 Hz had a lower pulse and blood pressure, better sleep and less perceived stress than those who received standard care. The control group listened to nothing, so the study cannot tell the effect of the frequency from the effect of daily quiet listening.

Two animal studies point the same way. In rats a 528 Hz sound reduced anxiety-related behaviour, and in zebrafish solfeggio-frequency music reversed the rise of cortisol caused by stress.

For the other eight tones no controlled studies in people exist. What is well established is the effect of music as such: a review of 104 randomised trials with 9,617 participants found that listening to music reduces stress, with a medium effect on how people feel and a smaller one on the body, clearest in the heart rate.

The claim that 528 Hz repairs DNA comes from Leonard Horowitz. No study has shown it in people.

What solfeggio frequencies are used for: sleep, anxiety, pain, focus

People rarely search for a number first. They search for a purpose. The table shows which tone sound therapy uses for which purpose, and what to combine it with in the generator.

The first column is the purpose for which the tradition uses the tone. The third column rests on firmer ground: the effects of delta, theta and alpha beats on sleep, relaxation and anxiety have been tested in dozens of studies, described on the pages about binaural beats.

How to listen to solfeggio frequencies

A pure tone is a demanding sound. It has no melody to follow and no rhythm to rest on, so the way you listen matters more than with music.

• Start low and short. Set the volume so that the tone is barely audible and listen for five minutes.
• Sit or lie down and close your eyes. Breathe slowly: in for a count of four, out for a count of six.
• Let the tone stay in the background. You do not have to concentrate on it.
• If the tone feels sharp, switch on the brown noise background or choose a lower tone.
• Extend to 15 or 20 minutes once it feels comfortable. For sleep use the timer so that the sound fades out.

Headphones are needed only when you add a binaural beat. A pure tone sounds the same through a speaker.

Solfeggio frequencies with binaural beats

A binaural beat needs two tones, one for each ear, and the tones must be below 1000 Hz. Every solfeggio frequency fits, so a solfeggio tone can carry a beat.

In the generator choose a tone and a beat. With 528 Hz and a theta beat the left ear hears 528 Hz, the right ear 534 Hz, and the brain hears a slow pulse of 6 Hz. The pitch is the solfeggio tone; the rhythm is the beat.

This is the combination most meditation recordings use, and it joins two different things: a tone chosen for its meaning in the tradition and a rhythm whose effects on relaxation, sleep and anxiety have been measured.

Solfeggio tuning forks: how to use them

Tuning forks are the oldest way to hear a pure tone. Solfeggio forks are sold singly and in sets of nine.

• An unweighted fork gives a clear tone in the air. Hold it a few centimetres from the ear.
• A weighted fork, with discs on the prongs, vibrates more strongly. Place its stem on the body.
• Strike the fork on a rubber activator or on the knee, never on a hard surface: metal on metal damages the fork and adds overtones.
• A fork sounds for 20 to 40 seconds. A generator holds the tone as long as you like and lets you add a beat or a background.

Are solfeggio frequencies safe

No study has described a harm specific to a solfeggio frequency. What can harm hearing is loudness and duration, whatever the frequency. The World Health Organization considers sound of up to 80 dB safe for 40 hours a week.

A pure tone tires the ear sooner than music at the same volume, and the high tones, 741, 852 and 963 Hz, are the most piercing. Headache, irritation or ringing in the ears are signs to lower the volume or stop. People with tinnitus or sensitivity to sound should start with 174 or 285 Hz at a very low volume.

With a binaural beat the usual rules apply: headphones, no listening while driving, and people with epilepsy should talk to their doctor first.

Is 432 Hz a solfeggio frequency

No, although the two are often listed together. 432 Hz is a tuning: music in which the note A is set to 432 Hz instead of the standard 440 Hz. It changes every note of a piece slightly, while a solfeggio frequency is one fixed tone.

432 Hz has more research than any solfeggio tone. In an Italian pilot study with 33 volunteers the same film music lowered the heart rate by almost five beats a minute more when it was tuned to 432 Hz. In a trial in Chile with 42 patients waiting for a tooth extraction, music in both tunings lowered anxiety, and salivary cortisol was lower with 432 Hz than with 440 Hz.