There is a tendency in Japan to adhere to strict classifications and distinctions. This is especially true in regards to music. Hogaku is one kind of music, Western classical is another. Pop and world music belong to yet other genres. Each genre is considered entirely separate, and performers, audiences and scholastic research rarely overlap.
So much for a liberal, ecumenical approach to music in Japan. The tendency for classification can be seen in the Japanese musical terminology as well. Although the Japanese kanji for music, ongaku, can be found in documents dating back as early as the 8th century, its meaning (and reading) has changed considerably throughout the ages.
Since the Meiji Era, ongaku has been considered a direct translation of the English "music" or the German word Musik. Furthermore, in general usage, ongaku (or more specifically, yogaku) came to designate Western music as opposed to the various traditional genres of Japanese music and performing arts, which suddenly became immensely important in Japan after the Meiji Restoration.