639 Hz – Communication and Community. This frequency enables creation of harmonious community and harmonious interpersonal relationships. It can be used for dealing with relationships problems – those in family, between partners, friends or social problems. It can be used to encourage the cell to communicate with its environment, and various body systems to communicate with each other more fluidly. This Solfeggio frequency enhances communication, understanding, tolerance and love. The 639 Hz frequency can also be used for communication with parallel worlds or spiritual spheres.