The term American folk music encompasses numerous music genres, variously known as traditional music, traditional folk music, contemporary folk music, vernacular 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 the British Isles, Mainland 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." American folk 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. Early American folk music Most songs of the Colonial and Revolutionary periods originated in England, Scotland and Ireland and were brought over by early settlers. According to ethnomusicologist Bruno Nettl, American folk music is notable because it "At its roots is an English folk song tradition that has been modified to suit the specific requirements of America." Therefore many American folk songs, such as those documented by the American Folklorist Francis James Child in his catalogue of ballads known as the Child Ballads, can be traced back to their pre-colonial origins in the British Isles. For example, "Barbara Allen" remains a popular traditional ballad originating in England and Scotland, which immigrants introduced to the United States. The murder ballad "Pretty Polly", indexed by another scholar of American folk music, George Malcolm Laws, is an American version of an earlier British song, "The Gosport Tragedy". The oldest surviving folk song of local Anglo-American origin is the ballad "Springfield Mountain" dating back to 1761 in Connecticut. The typical instruments played in early American folk music were the fiddle, the guitar, the mandolin, the mouth organ, the fife, and the dulcimer, although guitars went through a significant change as the previously popular English guitar was replaced around the 1830s by the Spanish guitar. In addition to ballads, American colonials also imported numerous English country dance tunes, mainly jigs, reels, and hornpipes, which were played during community dances or