Instrument and repertoire
The shakuhachi is a five-holed bamboo flute, with a historical connection to a sub-sect of Zen Buddhism called Fukeshū. The traditional pieces for shakuhachi are called honkyoku - 'fundamental pieces'.
My first experience of hearing shakuhachi honkyoku was profound, and it absolutely broke my musical world apart. The music I was familiar with up until that point was like a wall made of bricks. Each brick had even dimensions, nice straight lines of rhythm and melody, which fit together neatly to create a solid wall.
Honkyoku, on the other hand, seemed to use rough-hewn stones that did not fit together well at all. However, creating a neat wall was not the objective. Instead, gaps were intentionally allowed to exist between the stones. Through those gaps, I caught a glimpse of the void, and was awed.
I often recognise that same quality in many Japanese practices and objects nowadays. It's in the fit and utility of natural things, such as light and shadow, sound and silence.