Folk rock in the context of "Buffalo Springfield"

Folk music is a music genre that includes traditional folk music and the contemporary genre that evolved from the former during the 20th-century folk revival. Some types of folk music may be called world music. Traditional folk music has been defined in several ways: as music transmitted orally, music with unknown composers, music that is played on traditional instruments, music about cultural or national identity, music that changes between generations (folk process), music associated with a people's folklore, or music performed by custom over a long period of time. It has been contrasted with commercial and classical styles. The term originated in the 19th century, but folk music extends beyond that.

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. This form of music is sometimes called contemporary folk music or folk revival music to distinguish it from earlier folk forms. Smaller, similar revivals have occurred elsewhere in the world at other times, but the term folk music has typically not been applied to the new music created during those revivals. This type of folk music also includes fusion genres such as folk rock, folk metal, and others. While contemporary folk music is a genre generally distinct from traditional folk music, in U.S. English it shares the same name, and it often shares the same performers and venues as traditional folk music.

Contemporary folk music refers to a wide variety of genres that emerged in the mid-20th century and afterwards which were associated with traditional folk music. 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. The transition was somewhat centered in the United States and is also called the American folk music revival. Fusion genres such as folk rock and others also evolved within this phenomenon. While contemporary folk music is a genre generally distinct from traditional folk music, it often shares the same English name, performers and venues as traditional folk music; even individual songs may be a blend of the two.

While the Romantic nationalism of the first folk revival had its greatest influence on art music, the "second folk revival" of the later 20th century brought a new genre of popular music with artists marketed through concerts, recordings and broadcasting. One of the earliest figures in this revival was Woody Guthrie, who sang traditional songs in the 1930s and 1940s as well as composing his own. Other major performers who emerged from the 1940s to the early 1960s included Pete Seeger, Bob Dylan, Joan Baez, Peter, Paul and Mary, Phil Ochs and Tom Paxton. In the UK, the folk revival fostered a generation of musicians such as Fairport Convention, Richard Thompson, Donovan, Martin Carthy, and Pentangle, who achieved initial prominence in the 1960s. The folk revival spawned Canada's first folk wave of internationally successful artists such as Neil Young, Gordon Lightfoot, Leonard Cohen, Joni Mitchell, and Buffy Sainte-Marie.

Folk metal is a fusion genre of heavy metal music and traditional folk music that developed in Europe during the 1990s. It is characterised by the widespread use of folk instruments and, to a lesser extent, traditional singing styles (for example, Dutch Heidevolk, Danish Sylvatica and Spanish Stone of Erech). It also sometimes features soft instrumentation influenced by folk rock.

The earliest folk metal bands were Skyclad from England and Cruachan from Ireland. Skyclad's debut album The Wayward Sons of Mother Earth was released in 1991 and would be considered a thrash metal album with some folk influences, unlike Cruachan’s early work which embraced the folk element as a defining part of their sound. It was not until 1994 and 1995 that other early contributors in the genre began to emerge from different regions of Europe and beyond. Among these early groups, the German band Subway to Sally spearheaded a different regional variation that over time became known as medieval metal. Despite their contributions, folk metal remained little known with few representatives during the 1990s. It was not until the early 2000s when the genre exploded into prominence, particularly in Finland with the efforts of such groups as Finntroll, Ensiferum, Korpiklaani, Turisas, and Moonsorrow.

Sunshine pop (originally called soft pop and soft rock) is a loosely defined form of pop music that was first associated with early soft rock producers and songwriters based in Los Angeles, California, during the mid- to late 1960s. Its studio-centric sound was primarily rooted in folk rock and easy listening, typically featuring rich harmony vocals and progressive elements, while lyrics combined idyllic imagery with a subtle awareness of societal change, melancholic undertones, and countercultural themes. It was among the dominating music styles heard in television, film, and commercials of the era.

Branching from the nascent California sound, the movement initially straddled multiple styles among many groups who existed briefly while adapting to evolving music trends, resulting in much crossover with bubblegum, folk-pop, garage rock, baroque pop, and psychedelia. Most groups were less successful sound-alikes of acts such as the Mamas & the Papas, led by John Phillips, and the 5th Dimension, whose songs were initially helmed by Jimmy Webb. Curt Boettcher produced numerous key records for the Association, Eternity's Children, his band the Millennium, and with collaborator Gary Usher (Sagittarius). Though the Beach Boys rarely approached the style, Brian Wilson's production of their 1966 album Pet Sounds was a foundational influence on this milieu, as were the arrangements of Burt Bacharach.