of, relating to, or shaped like a triangle; having three angles; triangular. 2. Crystallography. having threefold symmetry. Origin of trigonal.
An online survey conducted in the U.S. points out that the most popular music genre in the U.S. is rock, with 40 percent of respondents choosing this option. The second and third most listened to music genres are oldies and country respectively, while hip hop/rap is favored by a smaller niche of American listeners.
Music Genre Popularity Chart on wiseGEEK: 1  Perhaps the largest music genres is rock and roll, an umbrella genre under which several other types of music can be categorized. Other major music genres include classical, folk, jazz, R&B, blues, metal, and world music. The term music genre is used to refer to a variety of facets of music, including the period during which a musical composition was written, its style, its instrumentation and treatment of those instruments, its form and function, its means of transmission, its means of dissemination, and the location of its geographical origins sometimes crossed with the cultural or ethnic background of the composer.