By Christine Stevens Christine Stevens leads Healing Sound Retreat, along with Silvia Nakkach, August 29–September 1  The following is an excerpt from Music Medicine, the Science and Spirit of Healing Yourself with Sound (Sounds True, 2012) We use the language of rhythm all the time. I feel “off-beat.” Happiness is called “up-beat.” We talk about feeling like “we got our groove back.” But dive deeper into this rhythm metaphor to the deep pulsing heartbeat that defines life itself, and you’ll discover that rhythm exists within and all around you. Playing drums and percussion can become a sacred invocation of this healing life force. Four Rhythms of Life We all have rhythm within us. This rhythm is so natural that we hardly notice the drum of who we are. The following are just a few examples of four rhythms we know from being alive that define the movement of life. 1. Heartbeat. The heartbeat rhythm is primal—the mother of all rhythms and the rhythm we first heard inside our mother’s womb. The groove of life ranges …