What was specific about his painting technique was that he would always try to involve the viewer of the painting by drawing eyes and the positioning of his characters in such a way that it always seems as if they're maintaining eye contact with the audience. This was done using various perspectives and is kind of like an illusion, similarly to how the Mona Lisa is painted.
Ethnomusicology ~ music study in many cultural contexts
Music History ~ study of Western art music
Music Theory ~ analyze music from a historical perspective as well as develop new techniques for analyzing current trends in music composition
Systematic musicology ~ Umbrella term for musicology