The term American folk music encompasses numerous music genres, variously known as traditional music, traditional folk music, contemporary folk music, or roots music. Many traditional songs have been sung within the same family or folk group for generations, and sometimes trace back to such origins as Great Britain, Europe, or Africa. Musician Mike Seeger once famously commented that the definition of American folk music is "...all the music that fits between the cracks."
Roots music is a broad category of music including bluegrass, gospel, old time music, jug bands, Appalachian folk, blues, Cajun and Native American music. The music is considered American either because it is native to the United States or because it developed there, out of foreign origins, to such a degree that it struck musicologists as something distinctly new. It is considered "roots music" because it served as the basis of music later developed in the United States, including rock and roll, rhythm and blues, and jazz.