Assigning music by genre is a subjective task.  Music is grouped on this site by:

 

This method was chosen after considerable trial and error, and recognition of our own limitations.  For example, we are relatively knowledgeable about rock music, but less so with country, where bluegrass could be separated, and jazz, where big band and swing could be separated, with jazz itself encompassing fusion, bop, and other sub-genres.  So in the interest of accuracy we have kept those genres broad, for now.

Note: some artists fit more than one genre or sub-genre, and are so categorized.