This frequency enables creation of harmonious community and harmonious interpersonal relationships. Tone Fa can be used for dealing with relationships problems – those in family, between partners, friends or social problems. When talking about cellular processes, tone Fa can be used to encourage the cell to communicate with its environment. This ancient solfeggio frequency enhances communication, understanding, tolerance and love. 639 Hz frequency can also be used for communication with parallel worlds or spiritual spheres.