In the group I belong to, it's mostly for the purpose of shamanic journeying. The drumbeat alters your brain waves to like when you're dreaming, to communicate with your deepest self/spiritual self/spirit guides to retrieve information. It's also useful for dream work - something we do a lot of in my therapy - yesterday I did a quick dream re-entry (the dream was about my mother) to ask her why she wouldn't do something in the dream. I got a pretty deep answer that I'm still thinking about! T has drummed for me before several times, so that's why I felt a little intimidated last night. But I did it. Anyways I know this is too woo-woo for some, but I love it.