The terms folk music, folk song, and folk dance are comparatively recent expressions. They are extensions of the term folklore, which was coined in 1846 by the English antiquarian William Thoms to describe "the traditions, customs, and superstitions of the uncultured classes". The term further derives 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. Though it is understood that folk music is the music of the people, observers find a more precise definition to be elusive. Some do not even agree that the term folk music should be used. 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."
The advent of audio recording technology provided folklorists with a revolutionary tool to preserve vanishing musical forms. The earliest American folk music scholars were with the American Folklore Society (AFS), which emerged in the late 1800s. Their studies expanded to include Native American music, but still treated folk music as a historical item preserved in isolated societies as well. In North America, during the 1930s and 1940s, the Library of Congress worked through the offices of traditional music collectors Robert Winslow Gordon, Alan Lomax and others to capture as much North American field material as possible. John Lomax (the father of Alan Lomax) was the first prominent scholar to study distinctly American folk music such as that of cowboys and southern blacks. His first major published work was in 1911, Cowboy Songs and Other Frontier Ballads. and was arguably the most prominent US folk music scholar of his time, notably during the beginnings of the folk music revival in the 1930s and early 1940s. Cecil Sharp also worked in America, recording the traditional songs of the Appalachian Mountains in 1916–1918 in collaboration with Maud Karpeles and Olive Dame Campbell and is considered the first major scholar covering American folk music. Campbell and Sharp are represented under other names by actors in the modern movie Songcatcher.
One strong theme amongst folk scholars in the early decades of the 20th century was regionalism, the analysis of the diversity of folk music (and related cultures) based on regions of the US rather than based on a given song's historical roots. Later, a dynamic of class and circumstances was added to this. The most prominent regionalists were literary figures with a particular interest in folklore. Carl Sandburg often traveled the U.S. as a writer and a poet. He also collected songs in his travels and, in 1927, published them in the book The American Songbag. Rachel Donaldson, a historian who worked for Vanderbilt, later stated this about The American Songbird in her analysis of the folk music revival. "In his collections of folk songs, Sandburg added a class dynamic to popular understandings of American folk music. This was the final element of the foundation upon which the early folk music revivalists constructed their own view of Americanism. Sandburg's working-class Americans joined with the ethnically, racially, and regionally diverse citizens that other scholars, public intellectuals, and folklorists celebrated their own definitions of the American folk, definitions that the folk revivalists used in constructing their own understanding of American folk music, and an overarching American identity".
Folk music festivals proliferated during the 1930s. President Franklin Roosevelt was a fan of folk music, hosted folk concerts at the White House, and often patronized folk festivals. One prominent festival was Sarah Gertrude Knott's National Folk Festival, established in St. Louis, Missouri in 1934. Under the sponsorship of the Washington Post, the festival was held in Washington, DC at Constitution Hall from 1937 to 1942. The folk music movement, festivals, and the wartime effort were seen as forces for social goods such as democracy, cultural pluralism, and the removal of culture and race-based barriers.
Music as professionalized paid entertainment grew relatively slowly in Canada, especially remote rural areas, through the 19th and early 20th centuries. While in urban music clubs of the dance hall/vaudeville variety became popular, followed by jazz, rural Canada remained mostly a land of traditional music. Yet when American radio networks began broadcasting into Canada in the 1920s and 1930s, the audience for Canadian traditional music progressively declined in favour of American Nashville-style country music and urban styles like jazz. The Americanization of Canadian music led the Canadian Radio League to lobby for a national public broadcaster in the 1930s, eventually leading to the creation of the Canadian Broadcasting Corporation (CBC) in 1936. The CBC promoted Canadian music, including traditional music, on its radio and later television services, but the mid-century craze for all things "modern" led to the decline of folk music relative to rock and pop. Canada was however influenced by the folk music revival of the 1960s, when local venues such as the Montreal Folk Workshop, and other folk clubs and coffee houses across the country, became crucibles for emerging songwriters and performers as well as for interchange with artists visiting from abroad.
In January 2012, the American Folklife Center at the Library of Congress, with the Association for Cultural Equity, announced that they would release Lomax's vast archive of 1946 and later recording in digital form. Lomax spent the last 20 years of his life working on an Interactive Multimedia educational computer project he called the Global Jukebox, which included 5,000 hours of sound recordings, 400,000 feet of film, 3,000 videotapes, and 5,000 photographs. As of March 2012, this has been accomplished. Approximately 17,400 of Lomax's recordings from 1946 and later have been made available free online. This material from Alan Lomax's independent archive, begun in 1946, which has been digitized and offered by the Association for Cultural Equity, is "distinct from the thousands of earlier recordings on acetate and aluminum discs he made from 1933 to 1942 under the auspices of the Library of Congress. This earlier collection—which includes the famous Jelly Roll Morton, Woody Guthrie, Lead Belly, and Muddy Waters sessions, as well as Lomax's prodigious collections made in Haiti and Eastern Kentucky (1937) — is the provenance of the American Folklife Center" at the library of Congress.
Sidmouth Festival began in 1954, and Cambridge Folk Festival began in 1965. The Cambridge Folk Festival in Cambridge, England is noted for having a very wide definition of who can be invited as folk musicians. The "club tents" allow attendees to discover large numbers of unknown artists, who, for ten or 15 minutes each, present their work to the festival audience.
For example, the words of "I'm a Man You Don't Meet Every Day" (Roud 975) were written down in a broadside in the 18th century, and seem to have an Irish origin. In 1958 the song was recorded in Canada (My Name is Pat and I'm Proud of That). Scottish traveler Jeannie Robertson from Aberdeen, made the next recorded version in 1961. She has changed it to make reference to "Jock Stewart", one of her relatives, and there are no Irish references. In 1976 Scottish artist Archie Fisher deliberately altered the song to remove the reference to a dog being shot. In 1985 The Pogues took it full circle by restoring the Irish references.
The four-day Philadelphia Folk Festival began in 1962. It is sponsored by the non-profit Philadelphia Folksong Society. The event hosts contemporary and traditional artists in genres including World/Fusion, Celtic, Singer-Songwriter, Folk Rock, Country, Klezmer, and Dance. It is held annually on the third weekend in August. The event now hosts approximately 12,000 visitors, presenting bands on 6 stages.
The post–World War II folk revival in America and in Britain started a new genre, Contemporary Folk Music, and brought an additional meaning to the term "folk music": newly composed songs, fixed in form and by known authors, which imitated some form of traditional music. The popularity of "contemporary folk" recordings caused the appearance of the category "Folk" in the Grammy Awards of 1959; in 1970 the term was dropped in favor of "Best Ethnic or Traditional Recording (including Traditional Blues)", while 1987 brought a distinction between "Best Traditional Folk Recording" and "Best Contemporary Folk Recording". After that, they had a "Traditional music" category that subsequently evolved into others. The term "folk", by the start of the 21st century, could cover singer-songwriters, such as Donovan from Scotland and American Bob Dylan, who emerged in the 1960s and much more. This completed a process to where "folk music" no longer meant only traditional folk music.
"Knowledge of the history of Canada", wrote Isabelle Mills in 1974, "is essential in understanding the mosaic of Canadian folk song. Part of this mosaic is supplied by the folk songs of Canada brought by European and Anglo-Saxon settlers to the new land." She describes how the French colony at Québec brought French immigrants, followed before long by waves of immigrants from Great Britain, Germany, and other European countries, all bringing music from their homelands, some of which survives into the present day. Ethnographer and folklorist Marius Barbeau estimated that well over ten thousand French folk songs and their variants had been collected in Canada. Many of the older ones had by then died out in France.