A master class is a class given to students of a particular discipline by an expert of that discipline—usually music, but also science, painting, drama, games, or on any other occasion where skills are being developed. "Masterclass" is also used in a figurative sense to describe a display of great skill in a context where education was not the primary intention; e.g., "his last few laps were a masterclass in overtaking" (referencing a race around a track). Source: Wikipedia (en)