A funny thing happened last year when Billy Bragg and Wilco released Mermaid Avenue, a collection of songs based on unrecorded Woody Guthrie lyrics: It sparked a flurry of interest in Billy Bragg and Wilco, which may not have been entirely what they had in mind. For those seeking a crash course in Guthrie, not to mention a massive, excellent collection showcasing one of the most important figures in American music, there's no better option than The Asch Recordings. A boxed, discount-priced collection of Guthrie performances recorded by Moses Aschwho made a career of recording every sort of American music, from folk to jazz to frog songs, that might otherwise have been lost to the agesthe set lacks only a handful of key songs from Guthrie's catalog. It represents the bulk of his commercial output, which in and of itself makes it essential. As a writer, interpreter, and singer, Guthrie gave a face and a voice to folk music during his brief performing and recording career. Pro-union, pro-humanity, and anti-fascist in both the literal and metaphorical sense of the term, Guthrie's body of work is that of both a brilliant and prolific songwriter and the finest channeling of the American folk tradition of his or any time. Titled This Land Is Your Land for Guthrie's most famous songa populist national anthem that stands in opposition to the militant "Star Spangled Banner"the first volume offers a nice overview of Guthrie's output as a songwriter. Its diverse subject matter ranges from labor songs ("Talking Hard Work") to folk blues ("Going Down The Road Feeling Bad") to children's songs ("Car Song") to timely protest numbers ("Lindbergh") to unfortunately timeless laments of inequity ("Pastures Of Plenty"). Volume two, Muleskinner Blues, places its emphasis on Guthrie as an interpreter of traditional music, while the third and fourth volumes, dealing with topical songs and Western numbers, respectively, combine Guthrie originals with adaptations of traditional music. Nothing here is less than essential, especially considering that without Guthrie there would be no Dylan, no Springsteen, and none of the many artists they themselves inspired. But to talk about Guthrie only in terms of those he influenced is to do a disservice to his own career, which this lovingly assembled and copiously annotated collection presents in the finest possible form over the course of more than 100 indispensable songs.