Zen Music is a form of music known as Koten Honkyoku - the largest and oldest collection of solo shakuhachi music that was written centuries ago by unidentified Komuso monks. It is not soothing, new agey music.

Zen Honkyoku music is a cultural music form and are specific, individually named and written pieces of music. It is played with demanding technical requirements from both the player and the flute.

Not all shakuhachi flutes are suitable or capable of playing Zen Honkyoku music. It is complex in timbre and pitch and uses many shaded fingerings that do
not work on lesser shakuhachi-like flutes. Honkyoku can sound atonal to Western ears because of the micro-tonal pitch bends and old Japanese musical intervals.