Bear Family split their 12-disc American folk retrospective into quarters: four sets covering roughly 1936 through 1972, each following a loose chronology but assembled to make big, broader points about the music's evolution. Even though this first volume reaches back as far as 1928 for the Carter Family's "Wildwood Flower," most of the music on the first disc of this edition dates from 1940 and beyond, with much of it dedicated to Woody Guthrie, who was undeniably the pivotal figure of '40s and '50s folk. Think of this as the companion set to Harry Smith's Anthology of American Folk Music. Where that collection curated the songs of the old, weird America, the Troubadours of Folk series traces the evolution of folk from a communal art to a personal one, one where the focus was often on the singer as much as the song. On this first volume, the spotlight is on Guthrie -- who has 11 songs on the first disc, including "Do Re Mi," "I Ain't Got No Home," "Grand Coulee Dam," and "This Land Is Your Land" -- and his immediate followers, most of whom comprised the great folk scare of the '50s. This starts to surface on the second disc, which concentrates on Pete Seeger and the Weavers, but also finds space to slip in some early Terry Gilkyson and Merle Travis' "Sixteen Tons," the latter showing how folk and country sometimes blurred the lines. Singers and songwriters alike comprise the third disc, which is devoted to the '50s: Cisco Houston, Jean Ritchie, and Oscar Brand are the heavy-hitters here, acts that often brought traditional songs into the mainstream, but Bob Gibson and Paul Clayton are the first signs that the spotlight was starting to shift from older songs to self-penned originals. In a sense, this is all a prelude to the explosion that takes place in the '60s in the wake of Bob Dylan, but this is both fascinating -- and entertaining -- history in its own right, history that's essential to the understanding of American song in the 20th century.