Folk music in the US is varied across the country's numerous ethnic groups. The Native American tribes each play their own varieties of folk music, most of it spiritual in nature. African American music includes blues and gospel, descendants of West African music brought to the Americas by slaves and mixed with Western European music. During the colonial era, English, French and Spanish styles and instruments were brought to the Americas. By the early 20th century, the United States had become a major center for folk music from around the world, including polka, Ukrainian and Polish fiddling, Ashkenazi, Klezmer, and several kinds of Latin music.