Master classes originate from the musical domain, but may also be applied to other domains with a high level of complexity. Since 2006 two-days master classes take place under patronage of the International Society for Gerontechnology (ISG). Teaching is meant for young researchers and designers, typically PhD students, who prepare their project for the master class. Master teachers are experi-enced in working at the crossroad of technology and gerontology. Project focussing, clar-ity and embedding in the academic literature of both technology and gerontology are the main teaching aims. The master class became the 4th pillar in the mission of the ISG, after biannual conferences, the journal Gerontechnology, and cultural chapters.