When father-and-son folklorists John and Alan Lomax hit the road in 1933 to record the blues, bluegrass, and folk music in the southern United States, the pair traveled with a 300-pound disc-cutting machine in the trunk of their car. In later years, Alan would make his famous field recordings with a somewhat lighter reel-to-reel tape recorder, capturing everything from prison work songs to tunes by Woody Guthrie.
The folk music recorded by the Lomax family, much of which is available for free online, along with the folk ballads of Odetta, spurred a rise in the popularity of the genre in the postwar years, particularly the 1960s, launching the careers of Bob Dylan, Joan Baez, and Phil Ochs, as well as groups such as The Weavers, The Kingston Trio, Peter, Paul and Mary, the Holy Modal Rounders, Simon & Garfunkel, and The Mamas & the Papas. Though generally considered sunnier and more mainstream than its grittier cousin—the blues—folk music was also the vehicle for most 1960s protest songs, enabling people around countless campfires to sing against the war in Vietnam or in praise of workers striking for better wages.
In the U.S., bands like the Byrds and Buffalo Springfield often used folk music to anchor their sound, while groups like the Beach Boys occasionally pulled a folk chestnut out of the archives to give it a fresh update, as in their 1966 hit "Sloop John B." Meanwhile, in the U.K., The Beatles regularly flirted with folk music (think "Norwegian Wood"), while other acts embraced it more fully—Donovan, The Incredible String Band, and Fairport Convention come to mind.
In more recent years, folk music has inspired bands and singer-songwriters alike to push the genre into the realms as varied as psych (Devendra Banhart) and punk (Violent Femmes). Naturally, much country music leans to folk, but so does a lot of alt-rock—in 1998, one such band, Wilco, teamed up with British singer-songwriter Billy Bragg to write music for unpublished Woody Guthrie lyrics, thus insuring that the folk-music circle would remain unbroken.