Folk music includes both traditional music and the genre that evolved from it during the 20th century folk revival. The term originated in the 19th century but is often applied to music that is older than that. Certain types of folk music are also called world music.
Traditional folk music has been defined in several ways: as music transmitted by mouth, as music of the lower classes, and as music with unknown composers. It has been contrasted with commercial and classical styles. One meaning often given is that of old songs, with no known composers; another is music that has been transmitted and evolved by a process of oral transmission or performed by custom over a long period of time.
Starting in the mid-20th century a new form of popular folk music evolved from traditional folk music. This process and period is called the (second) folk revival and reached a zenith in the 1960s. The most common name for this new form of music is also "folk music", but is often called "contemporary folk music" or "folk revival music" to make the distinction. This type of folk music also includes fusion genres such as folk rock, folk metal, electric folk, and others. While contemporary folk music is a genre generally distinct from traditional folk music, in English it shares the same name, and it often shares the same performers and venues as traditional folk music. Even individual songs may be a blend of the two.
A consistent definition of traditional folk music is elusive. The terms folk music, folk song, and folk dance are comparatively recent expressions. They are extensions of the term folk lore, which was coined in 1846 by the English antiquarian William Thoms to describe "the traditions, customs, and superstitions of the uncultured classes." The term is further derived from the German expression Volk, in the sense of "the people as a whole" as applied to popular and national music by Johann Gottfried Herder and the German Romantics over half a century earlier. Traditional folk music also includes most indigenous music
However, despite the assembly of an enormous body of work over some two centuries, there is still no certain definition of what folk music (or folklore, or the folk) is. Folk music may tend to have certain characteristics but it cannot clearly be differentiated in purely musical terms. One meaning often given is that of "old songs, with no known composers", another is that of music that has been submitted to an evolutionary "process of oral transmission.... the fashioning and re-fashioning of the music by the community that give it its folk character."Such definitions depend upon "(cultural) processes rather than abstract musical types...", upon "continuity and oral transmission...seen as characterizing one side of a cultural dichotomy, the other side of which is found not only in the lower layers of feudal, capitalist and some oriental societies but also in 'primitive' societies and in parts of 'popular cultures'." One widely used definition is simply "Folk music is what the people sing".
For Scholes, as well as for Cecil Sharp and Béla Bartók, there was a sense of the music of the country as distinct from that of the town. Folk music was already "seen as the authentic expression of a way of life now past or about to disappear (or in some cases, to be preserved or somehow revived)," particularly in "a community uninfluenced by art music" and by commercial and printed song. Lloyd rejected this in favour of a simple distinction of economic class yet for him true folk music was, in Charles Seeger's words, "associated with a lower class" in culturally and socially stratified societies. In these terms folk music may be seen as part of a "schema comprising four musical types: 'primitive' or 'tribal'; 'elite' or 'art'; 'folk'; and 'popular'."
Music in this genre is also often called traditional music. Although the term is usually only descriptive, in some cases people use it as the name of a genre. For example, the Grammy Award previously used "traditional music" for folk music that is not contemporary folk music.
