174 Hz is one of the two tones added below Puleo's original six to round the Solfeggio set into a fuller scale. The tradition describes it as a foundation, a grounding, settling pitch. It is used as a low base tone to anchor a practice. The meaning belongs to the extended Solfeggio lore. As the Solfeggio set spread, two additional tones were placed below the original six to round the sequence into a fuller nine-note scale. They carry the same numeric signature as the rest and are described in the same tradition as grounding, foundational pitches rather than centres of the chakra ladder. Independent of any tradition, controlled clinical evidence that a specific frequency produces a specific health effect is limited and mixed. Auriviel presents these tunings as music and contemplative practice. This page is for general information and relaxation. Auriviel's frequency music is not medical advice, diagnosis, or treatment, and no health outcome is claimed. If you have a medical concern, please consult a qualified professional.