Each Tuesday evening in North Hollywood, California, the roof of the Remo Percussion Center is raised by the thunderous thythms of 100 and more beating drums, as musicians and nonmusicians alike sit in circles and bang their way to better health.

Drumming circles, which are springing up in dozens of locations nationwide, are among the country's fastest-growing holistic health trends. Enthusiastic advocates say that this pastime reduces stress and anger, boosts the immune system and induces pleasure and relaxation. "Drumming is innate within us because of our own inner rhythms -- our heartbeats, our breathing, our brain waves," says psychotherapist Robert Lawrence Friedman, author of The Healing Power of the Drum, who practices a program with corporate employees called "Drumming Away Stress." "The drumbeat can help people express unarticulated emotions and reach deep levels of relaxation. It also frees the spirit, and I'm a believer in the power of play to heal."

Scientific support for the benefits of drumming is mounting. Physicians are finding that Alzheimer's patients who drum can connect better with loved ones, and researchers have discovered that hearing slow, steady rhythms, such as drumbeats, helps Parkinson's patients move more steadily.

So far, the most conclusive evidence of positive health effects comes from neurologist Dr. Barry Bittman, medical director of the Mind-Body Wellness Center in Meadville, Pennsylvania. He found that, in 111 healthy people, drumming significantly raised levels of natural killer cells, produced by the immune system to fight disease. Bittman is doing further research with elderly people and cancer patients. "Of the many ways drumming makes us well, one is that, when people are given the opportunity to make music and express themselves, they immediately come to life." For more details, click to www.remo.com and www.drumcircle.org.