Historical musicology, ethnomusicology, systematic musicology, and music theory
Sudden enlightenment is the answer in this question. This statement used as a metaphor to express the sudden enlightenment, the Zen priest-painters used a painting technique which they called haboku a splashed ink. In short the thing they called haboku used as a metaphor to express sudden enlightenment.
In archaeology, rock art is human-made markings placed on natural stone; it is largely synonymous with parietal art. A global phenomenon, rock art is found in many culturally diverse regions of the world. It has been produced in many contexts throughout human history, although the majority of rock art that has been ethnographically recorded has been produced as a part of ritual. Such artworks are often divided into three forms: petroglyphs, which are carved into the rock surface, pictographs, which are painted onto the surface, and earth figures, formed on the ground. The oldest known rock art dates from the Upper Palaeolithic period, having been found in Europe, Australia, Asia and Africa. Archaeologists studying these artworks believe that they likely had magico-religious significance.