Schumman Resonance

Integratron an "acoustically perfect structure," give tours and offer "sound baths" they describe as "...meditation-like sessions accompanied by tones from quartz bowls.
https://en.wikipedia.org/wiki/Integratron
Anthony Bourdain visits the Integratron.
http://www.travelchannel.com/shows/anthony-bourdain/video/an-acoustic-anomaly

A Tuning Fork for Life Although the existence of the Schumann Resonance is an established scientific fact, there are very few scientists who are aware of the importance of this frequency as a tuning fork for Life. I propose that it is not merely a phenomenon caused by lightning in the atmosphere, but a very important electromagnetic standing wave, acting as background frequency and influencing biological oscillators within the mammalian brain.
http://www.earthbreathing.co.uk/sr.htm

Biofield Tuning   The thing is, you can’t make a 7.83 Hz tuning fork – so I played around with multiples of it, harmonics – and the 8th harmonic (7.83Hz x 8) is 62.64 Hz. I liked the sound of that number, so I had a fork custom made in that frequency. Wow! I couldn’t believe how wonderful and powerful and useful this frequency was compared to all the other ones I had used.
https://biofieldtuning.com/tuning-forks-used-sound-balancing-part-2-weighted-forks/

Tuning Fork Therapy  

This is a listing of frequencies that various parties have claimed can affect the human mind or body in some way. The following sorts of frequencies are included :   Brainwave Frequencies - These are frequencies associated with various mental states. Using brainwave entrainment, you can coax your brainwaves to a certain frequency, and in doing so, achieve the mental state associated with that frequency.  

 The rest of the article and list.......http://www.tuningforktherapy.com/about_16.html