Rhys Chatham is a member of the Association of Professional Astrologers International (MAPAI) and OPA/AFAN. He began studying 20th century astrology with Charles and Vivian Jayne in the late 1960s and 1970s, before pursuing extensive further formal training: completing Chris Brennan's full Hellenistic astrology course and horary course, natal and horary courses with Christopher Warnock including astrological magic, and an advanced Master Diploma in primary directions with Dr. Martin Gansten in August 2023. He also completed the School of Traditional Astrology's Horary Practitioner's course, studying under Deborah Houlding, Lee Lehman, Eve Dembowski, and Wade Caves, leading to the Advanced Horary Diploma in November 2022. He is a hermetic kabbalist and has been a member of esoteric lodges in the United Kingdom since 2000. He has spoken at international conferences including the Astrological Lodge of London, AFAN, and Kepler College.