The four major musical genres in the United States are:
1) Rock - A genre that originated in the 1950s, rock music is characterized by a heavy emphasis on guitars and drums, and is often considered to be rebellious and youthful. Some of the most popular rock bands include The Beatles, Led Zeppelin, and Nirvana.
2) Hip-Hop/Rap - A genre that emerged in the 1970s, hip-hop/rap music is defined by its use of rhyming lyrics and catchy beats. Some of the most popular hip-hop/rap artists include Jay-Z, Eminem, and Kanye West.
3) Country - A genre that has its roots in folk music, country music is known for its twangy guitars and sentimental lyrics. Some of the most popular country artists include Garth Brooks, Taylor Swift, and Carrie Underwood.
4) Jazz - A genre that developed in the early 20th century, jazz is characterized by its complex harmonies and improvisational style. Some of the most popular jazz musicians include Miles Davis, Louis Armstrong, and Duke Ellington.