Some of the performing arts of Japan are so spectacular that they grab your attention and immediately make you feel a part of the music. Taiko drumming is one; rhythm speaks directly to our bodies, and the beating of a stick on a drum has a physical appeal to all, regardless of language or culture.
Instrumental music is easily exportable. Song doesn't fare quite as well. To many non-Japanese, the vocal music of this country remains alien and unapproachable. Something about not being able to understand the meaning of the words causes otherwise sensitive Westerners, confronted with Japanese song, to shut their ears.
This is a pity -- especially considering that most of Japanese music is vocally oriented. The truth is, one doesn't have to understand the lyrics to appreciate the music. In many genres, not only are the words of the lyrics somewhat archaic, but also the vowel sounds are so elongated and sustained over a series of notes (a technique known as melisma) that even native speakers have trouble making out the meaning.