In Zen Buddhism a koan is an enigmatic and apparently illogical question which serves as a focus for the mind to concentrate on the problem of essential nature. The koan is presented as a puzzle that must be solved by the student in order to practise an inquiring attitude beyond dualistic thinking. I was interested in exploring a musical context where the shakuhachi sets the pace for the evolution of the poetic and psychological investigation of such a circumstance. Koan is based on a haiku form containing 17-syllable musical verses.