When browsing the iTunes Store, you can choose to view content from a number of genres. You can choose, for example, from Alternative, Classical, Electronic, Jazz, Rock and More. But the iTunes Store actually holds many more genres than what display in its popup menus. You just need to find them.
To access these “hidden” genres, scroll down to the bottom of a page in the iTunes Store, and, in the Features section of the footer, click Browse. This takes you to a column browser, where you can browse through all the content in the iTunes Store. Click Music, and you’ll see dozens of genres, including Chinese, Enka (?), Marching, New Age, and much more. You can’t see what’s new in these genres, but you can browse artists and albums if you’re interested in any of them.