Reiki and harp music deliver healing frequencies through a process called entrainment. Entrainment seems to have been first noticed by a European craftsman in the mid-1600s who built pendulum clocks, Christian Huygens. One day he noticed that all of the clock pendulums were moving together. No matter how he tried to change their swings, they would quickly come back into synchronization. Later scientific studies would show that all pendulums. . .indeed all vibrating things. . .would tend to swing in rhythm with the strongest one in the room.
In his book The World is Sound, Joachim-Ernst Berendt writes, "Science has taught us that [entrainment] is universal. Two oscillators pulsating in the same field in almost identical rhythm will tend to lock in, with the result that eventually their vibrations will be come precisely synchronous. This phenomenon is referred to as mutual phase-locking or entrainment. Entrainment is universal in nature.
“In fact, it is so ubiquitous that we hardly notice it,” he continues. “It is a physical phenomenon, but it is more than that, because it informs us about the tendency of the Universe to share rhythms, that is to vibrate in harmony."
Entrainment in Practice
So it may be that when a Reiki practitioner begins the flow of Reiki, entrainment is happening in the Human Energy Field and in the physical body. As the Reiki practitioner’s hands emit healing frequencies, the client's energy field and body will tend to resonate with the healthy frequencies for two reasons: 1) it is the body’s natural vibration and it wants to return there, and 2) Reiki energy from a practitioner is more concentrated and focused than the body’s energy. Reiki energy is “the strongest one in the room,” so the body’s energy will entrain to it.