Solfeggio frequencies list: what each one is and what the evidence says

What are the solfeggio frequencies?

The solfeggio frequencies are a list of nine pure tones, from 174 Hz to 963 Hz, that are each said to support a different emotional or spiritual goal. If you searched for a solfeggio frequencies list, the table below is the version you will see most often. A pure tone is a single, steady pitch with no other notes mixed in.

The name comes from the medieval hymn “Ut queant laxis”, whose lines gave us the syllables ut, re, mi, fa, sol and la. The hymn set out a singing scale, not frequencies: hertz, the unit for vibrations per second, came centuries later. The six core numbers were popularised in the 1990s, and three more (174, 285 and 963 Hz) were added after that.

Solfeggio frequencies list: what each one is said to do

These meanings are tradition and claims, collected from the books and websites that spread the set. They are not research findings.

Frequency	Syllable	What people associate it with
174 Hz		Grounding, easing physical tension
285 Hz		Restoring the body, a sense of safety
396 Hz	Ut	Letting go of fear and guilt
417 Hz	Re	Change, clearing the past
528 Hz	Mi	Transformation, often called the “love frequency”
639 Hz	Fa	Connection and relationships
741 Hz	Sol	Expression, problem solving
852 Hz	La	Intuition, returning to inner balance
963 Hz		Spiritual connection, a sense of oneness

Sources also pair each tone with a chakra, an energy centre in yogic tradition, usually 396 Hz with the root and 963 Hz with the crown. The pairings differ from list to list, which is one sign they are a convention rather than a measurement.

Some claims go further, for example that 528 Hz repairs DNA. No study supports that.

Are solfeggio frequencies scientifically proven?

No. Of the nine frequencies, 528 Hz is the only one with a published human study that we could find, and it was very small. The rest have not been tested in controlled trials that we could find.

In that 2018 study, nine healthy adults listened to the same music for five minutes, tuned either to 528 Hz or to the standard 440 Hz. After the 528 Hz version, their saliva showed lower cortisol, a stress hormone, and they reported less tension. Nine people is far too few to draw a firm conclusion, and the study has not been repeated at scale. You can read more in our article on 528 Hz.

What is well established is simpler: quiet, steady sound that you like can help you relax, whichever number it is tuned to. A pleasant tone may do some good for that reason alone.

Is 432 Hz a solfeggio frequency?

No. 432 Hz is an alternative tuning for the note A, used instead of the international standard of 440 Hz. It belongs to a debate about how to tune music, not to the solfeggio list, but the two are often mentioned together.

It has also been studied once. In a 2019 pilot study, 33 volunteers listened to 20 minutes of film music tuned to 432 Hz on one day and 440 Hz on another. Their heart rate was on average 4.79 beats per minute lower with the 432 Hz version, a result right at the edge of statistical significance. The authors called for larger trials. Our 432 Hz guide covers the details.

Which solfeggio frequency is best for sleep?

No solfeggio frequency has been shown to help sleep, so the honest answer is the one you find most restful. Many people pick 174 Hz or 528 Hz because lower and middle tones tend to sound softer at low volume.

If sleep is your main goal, a delta binaural beat (2 to 4 Hz) has more research behind it than any solfeggio tone, though that evidence is also mixed. Our guide to the best frequency for sleep compares the options. Many people combine the two: a solfeggio tone for its sound, with a slow beat underneath.

How do you listen to solfeggio frequencies?

A solfeggio frequency is an ordinary tone, so you can hear it through speakers or headphones. That is different from a binaural beat, which needs headphones because each ear must hear its own tone.

• Keep the volume low, just above the point where you can hear it.
• Try 10 to 20 minutes before deciding whether you like a tone.
• Layer it under rain or brown noise if a pure tone feels too bare.

In Shimmr, the library has solfeggio sessions from 174 to 963 Hz, plus 432 Hz. In the mixer you can add nature ambience, noise or your own music underneath.