Drumming is one of the oldest and best known methods to bring the spirit from the left hemisphere of your brain into the right one. Through a rapid, repetitive drum rhythm of 3-7 Hz brain waves adapt to the acoustic stimulus and form a pure sine wave, which is typical for deep meditation and trance states. It is said of this rhythm that it is the heartbeat of Mother Earth. This has now been confirmed by geophysical measurements which have shown an expansion and contraction of the earth in this rhythm. Even mothers who want to soothe their newborns weigh them instinctively in the same rhythm.