The latest chapter in Columbia/Legacy's highly acclaimed Bob Dylan Bootleg Series revisits Dylan's pivotal musical journeys to Nashville, from 1967 to 1969, focusing on previously unavailable recordings made with Johnny Cash and unreleased tracks from the  John Wesley Harding,  Nashville Skyline, and  Self Portrait sessions. Disc One of  Travelin' Thru, 1967 - 1969: The Bootleg Series Vol. 15 finds Dylan in Columbia's Studio A in Nashville recording alternate versions of compositions written for  John Wesley Harding (October 17 and November 6, 1967) and  Nashville Skyline (February 13-14, 1969) while introducing a new song "Western Road" (a  Nashville Skyline outtake). Discs Two and Three of  Travelin' Thru are centered around Dylan's collaborations with American music icon Johnny Cash including the much sought-after Columbia Studio A sessions and on-stage performances at the Ryman Auditorium (May 1, 1969) for the recording of the premiere episode of  The Johnny Cash Show (originally broadcast on ABC-TV on June 7, 1969). Disc Three closes with tracks recorded on May 17, 1970 with Grammy Award-winning bluegrass banjo legend Earl Scruggs for the PBS television special, "Earl Scruggs: His Family and Friends" (originally aired January 1971). 1967 saw a profound and surprising transformation in Bob Dylan's musical evolution. With contemporary pop culture becoming increasingly baroque, surreal and psychedelic in the wake of Dylan's 1965-66 cutting edge trilogy,  Bringing It All Back Home/ Highway 61 Revisited/ Blonde On Blonde, the artist withdrew from public view following a motorcycle accident in July 1966. He'd recorded  Blonde On Blonde with a full-band in Nashville in February 1966 but, when it came time to record its follow-up in the fall of 1967, he opted for a simple trio--Dylan (guitar, vocals, harmonica), Charlie McCoy (bass) and Kenneth Buttrey (drums)--to create a sublime minimal sound. In his liner notes for  Travelin' Thru,Colin Escott writes, "Talking to journalist Matt Damsker about the sound of  John Wesley Harding, Dylan said, 'I didn't know how to record the way other people were recording, and I didn't want to… Ijust didn't think all that production was necessary.'He also went for lyrical economy. 'What I'm trying to do now is not use too many words,' he said. 'There's no line you can stick your finger through. There's no blank filler.'" Dylan returned to Columbia Studio A in February 1969 to work on  Nashville Skyline. "Bob asked me to be a guest on the album," Johnny Cash said later, "and I went to the studio and they just turned on the recorder for about two hours." Columbia Studio A hosted two Dylan-Cash sessions: February 17 and 18, 1969 with a band that included rock 'n' roll pioneer Carl Perkins playing guitar on six tracks (including his own composition, "Matchbox"). One of the more intriguing sonic discoveries on  Travelin' Thruis "Don't Think Twice, It's Alright/Understand Your Man," as two singular singer/songwriters pay...