These tuning Forks are based on the solfeggio frequencies and were created by Dr Len Horowitz. The Solfeggio/Holy Harmony™ Tuning Forks contain the 9 tones that are frequently referred to as the “Original Solfeggio Scale”. When sounded individually or with each other, these tuning forks create a powerful field of frequencies for health and balance. When sounded around the body, many people report profound healing and prayerful meditation experiences.