Doc Watson may have recorded for many labels over the years, but the folks at Vanguard Records have wisely recognized their cut of the pie (from 1963 to 1971) as some of Watson's most seminal work. As a result, they've issued this cohesive and complex document of Watson's most influential period of artistic growth. By definition, The Vanguard Years is not a completist's collection, although it is an expansive project (64 songs over four discs), and much of Watson's most popular work is represented here. More interesting, though, is the lesser-known material, on which Watson can be heard evolving his famous flatpicking style that, as noted in the elegant liner notes, "made complex fiddle tunes come alive on guitar." The set opens audaciously with a short, wispy version of "Rambling Hobo", recorded live at the 1963 Newport Folk Festival. An intrepid style for folk music at the time, it sets a tone of innovation that pulls you breathlessly through the rest of the first disc, a study of musical exploration that rivals the great jazz instrumentalists of the same era. Particularly stirring is the spooky, music-box rendition of "Grandfather's Clock." Discs two and three focus on Watson's astonishing ability to inform simple, traditional compositions with passion and soul. His haunting take on "Rising Sun Blues" eclipses subsequent versions, and on "Talk About Suffering", "Omie Wise", and many other songs, it's Watson's stoic vocals that shine. As an accomplished guitarist, Watson often is overlooked as a vocalist. Here, his voice is presented as a vital element of his interpretive talents. By the end of the third disc, even the familiar standards sound fresh again. This is largely because Vanguard has done a remarkable job improving the sound quality on much of Watson's earlier work. By comparison, disc four -- a collection of 17 unreleased live cuts -- is a minor dissapointment. The audio quality takes a dive, and there's little here that isn't already captured on the richer, earlier material. Still, it's a hoot to hear Watson getting a charge out of his son Merle's solo during their duet on "Salt Creek". Watson is quoted as saying he believed "clinging to our traditional roots is what has kept us alive in the music business." While this may be true, The Vanguard Years is a definitive statement on Watson as an innovator. But it also stands as a testament to the effect a musician's label can have on their career. Vanguard obviously shared Watson's love of music and cleared the way for him to grow as an artist. That kind of relationship is rare, and it's what makes this collection so essential.