639 Hz: Meaning, Benefits & How to Listen
639 Hz is the fourth tone of the original solfeggio scale. It is traditionally linked to connection, relationships and the heart, which makes it popular for loving-kindness meditation. Here is what 639 Hz is, what it is traditionally associated with, what research does and doesn’t say, and how to listen.
What is 639 Hz?
A frequency of 639 hertz (Hz) is a sound wave that vibrates 639 times per second. On a piano it sits between D#5 (about 622 Hz) and E5 (about 659 Hz).
639 Hz is one of the nine solfeggio frequencies: 174, 285, 396, 417, 528, 639, 741, 852 and 963 Hz. The modern list became popular in the 1990s through the authors Joseph Puleo and Leonard Horowitz, who linked six of the tones to a medieval Latin hymn to St John the Baptist. The first syllables of that hymn (ut, re, mi, fa, sol, la) gave us the do-re-mi scale. 174, 285 and 963 Hz were added to the set later.
Why is 639 Hz linked to relationships?
639 Hz is linked to the syllable “fa” in the hymn behind the solfeggio scale. In the tradition it is associated with harmony, understanding and connecting with others. It is most often connected with the heart chakra (Anahata), though chakra mappings vary.
What does the research say?
You may read that 639 Hz will attract love or repair a relationship. That is a spiritual belief, not something research has shown.
There is no reliable scientific research on 639 Hz specifically. The meanings above come from spiritual and sound-healing traditions, not from clinical studies. What research on relaxing music in general does suggest is that calm, steady sound can help many people feel more relaxed and wind down. That is the honest way to think about 639 Hz: a pleasant tone that many people enjoy for meditation and rest.
What people use 639 Hz for
Loving-kindness meditation: a calm tone while you send kind thoughts to yourself and others.
Heart chakra practice: as part of a chakra meditation sequence.
Reflection: quiet listening before a difficult conversation.
Relaxing together: soft background sound for a calm evening.
Gratitude journaling: a gentle backdrop while you write.
How to listen to 639 Hz
Choose a pure 639 Hz tone, or music layered with 639 Hz if you prefer something softer.
Keep the volume low. It should sit in the background, not fill the room.
Use speakers or headphones. Unlike binaural beats, a single tone does not need headphones.
Start with 10 to 20 minutes. For sleep, play a longer track through the night.
Place a hand on your chest and breathe slowly, thinking of someone you care about.
639 Hz vs 528 Hz
639 Hz and 528 Hz are both linked to the heart. 528 Hz, the “love frequency”, is associated with transformation, while 639 Hz is associated with connection and relationships. Many people move from 528 Hz to 639 Hz in a single session.
Listen to 639 Hz
Long 639 Hz sleep and meditation videos are coming to our Healing Sounds YouTube channel. Subscribe to get them when they go live.
Try 639 Hz in the Healing Sounds app
Healing Sounds is a free app with 500+ sounds, including solfeggio frequencies from 174 Hz to 963 Hz, binaural beats, Tibetan singing bowls, nature sounds and white, brown and pink noise. You can layer 639 Hz with rain or ocean sounds to make your own mix for sleep or meditation.
Frequently asked questions
What chakra is 639 Hz?
639 Hz is most often linked to the heart chakra (Anahata), though chakra mappings vary between teachers.
Can 639 Hz attract love?
That is a spiritual belief rather than a measured effect. Many people use it as a calm tone for reflection and connection.
Do I need headphones for 639 Hz?
No. A single 639 Hz tone works the same through speakers or headphones. Headphones are only needed for binaural beats, which play a different frequency in each ear.
How long should I listen to 639 Hz?
Start with 10 to 20 minutes during meditation or a break. For sleep, many people play a longer track at a low volume through the night.
Is listening to 639 Hz safe?
For most people, listening to soft tones at a low volume is fine. Keep the volume low, and if you have tinnitus or another hearing concern, check with your doctor first.
Explore other frequencies
This article is for general information about relaxation and sound. It is not medical advice. If you have a health or mental health concern, please talk to your doctor.
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