Music held to be typical of a nation or ethnic group, known to all segments of its society, and preserved usually by oral tradition.
Knowledge of the history and development of folk music is largely conjectural. Musical notation of folk songs and descriptions of folk music culture are occasionally encountered in historical records, but these tend to reflect primarily the literate classes' indifference or even hostility. As Christianity expanded in medieval Europe, attempts were made to suppress folk music because of its association with heathen rites and customs, and uncultivated singing styles were denigrated. During the Renaissance, new humanistic attitudes encouraged acceptance of folk music as a genre of rustic antique song, and composers made extensive use of the music; folk tunes were often used as raw material for motets and masses, and Protestant hymns borrowed from folk music. In the 17th century folk music gradually receded from the consciousness of the literate classes, but in the late 18th century it again became important to art music. In the 19th century, folk songs came to be considered a "national treasure," on a par with cultivated poetry and song. National and regional collections were published, and the music became a means of promoting nationalistic ideologies. Since the 1890s, folk music has been collected and preserved by mechanical recordings. Publications and recordings have promoted wide interest, making possible the revival of folk music where traditional folk life and folklore are moribund. After World War II, archives of field recordings were developed throughout the world. While research has usually dealt with "authentic" (i.e., older) material not heavily influenced by urban popular music and the mass media, the influence of singer-songwriters such as Woody Guthrie , Pete Seeger , Joan Baez , and Bob Dylan expanded the genre to include original music that largely retains the form and simplicity of traditional compositions.