The Solfeggio Frequencies and Their Reception

The solfeggio frequencies as Horowitz and Puleo present them, 396, 417, 528, 639, 741 and 852 Hz, are marketed as a lost ancient musical scale once used in Gregorian chant and encoded with the numerological pattern Puleo claims to have found in scripture, restored to modern use through their book. Musicologists and historians of chant who have examined the claim find no documented historical basis for these specific frequencies in the medieval solmization tradition of Guido of Arezzo, whose syllables named scale degrees relative to a movable reference pitch rather than fixing tones at the specific modern-standard frequencies Horowitz and Puleo cite; the "ancient" and "suppressed" framing of the frequencies is regarded by specialists in the field as invented marketing rather than recovered history.

That skeptical academic consensus has not slowed the frequencies' spread through wellness culture, where 528 Hz in particular is marketed on tuning fork sets, meditation apps and sound bath recordings as a scientifically validated tool for healing and DNA repair, a claim with no support in peer-reviewed biology. Horowitz has continued to promote the frequencies and a wider set of alternative health and conspiracy claims across self-published books and documentary media into the 2020s, remaining the primary public face associated with solfeggio frequency practice even as the historical claims underneath it have been repeatedly and specifically rebutted.