There's a delicious moment on the fifteenth volume of Bob Dylan's long-running Bootleg Series. The troubadour is in Columbia Records' Nashville Studio A, rehearsing a duet medley with Johnny Cash of his "Don't Think Twice, It's All Right" and Cash's "Understand Your Man." Once they stop playing, The Man in Black happily observes that "the phrasing comes out just right, 'cause we both stole it from the same song!" Indeed, Dylan and Cash shared substantial musical roots, with less than a decade separating their births. With both signed to Columbia, and Dylan exploring country music in Music City, it was inevitable that their paths would cross in the studio. Their joint sessions of February 18 and 19, 1969 provide the beating heart of Travelin' Thru: The Bootleg Series Vol. 15 (1967-1969).

The set chronicles Dylan's sojourns to Nashville, the city which saw him record a number of his greatest successes and to which he hasn't returned to a studio since May 3, 1969. Travelin' Thru is a bit different than previous Bootleg sets; as Ben Rollins notes in his introduction, "the outtakes [for John Wesley Harding and Nashville Skyline] differ only slightly from one another. Consequently, in compiling this album the producers opted not to include multiple takes of the same song; rather, they looked for those takes that either give you an inkling of the creative process or illuminate a different approach to a song." The same approach informed the presentation of the Cash sessions. Lastly, Dylan collectors will notice that some tracks from the aforementioned albums are not represented here at all; some tapes have not survived. But that's not to say that this set - available on three CDs or three LPs - feels incomplete. This period encompassed some of Dylan's most vibrant music, and the alternate versions on Travelin' Thru once again open a very welcome window onto his in-studio process.

John Wesley Harding, recorded in October-November 1967 and released that December, followed the incendiary rock trilogy of Bringing It All Back Home (1965), Highway 61 Revisited (1965), and Blonde on Blonde (1966). It also followed Dylan's much-publicized motorcycle accident, arriving at a time when the anticipation of new music from the young superstar was at an all-time high. Recorded with just two Nashville cats - drummer Kenny Buttrey and bassist Charlie McCoy - plus steel guitarist Pete Drake on two tracks (not included here) and producer Bob Johnston, John Wesley Harding returned Dylan to a folk-influenced milieu. His songwriting was becoming earthier and less abstract, a style he would take further on Nashville Skyline.

Seven out of the album's twelve songs, the most justly famous of which is "All Along the Watchtower" (later popularized by Jimi Hendrix), are presented here in alternate versions recorded on October 17 and November 6, 1967. Dylan crafted new ballads in folk style like "Drifter's Escape" and "I Dreamed I Saw St. Augustine," creating vivid characters with colorful imagery. But many of the arrangements were conjured on the spot, and sometimes the songs, too. Anyone with a passing familiarity with the original LP will hear variations big (a totally different tempo - waltz time! - for "As I Went Out One Morning," an almost totally different melody for "I Pity the Poor Immigrant," a casual swing lilt on "I Am a Lonesome Hobo") and small (a harmonica part is missing here, a word is altered there) on these seven cuts.

In contrast, Nashville Skyline's February 1969 recording sessions would seem to reveal a more intentionally refined Dylan, certainly in terms of his writing. The singer-songwriter overtly embraced the sound and style of the country genre, transforming his nasal yowl into a warm croon to introduce a new set of songs. These tunes were lyrically economical, melodically rich, and frequently romantic. Joining him in the studio was returning producer Johnston, and a group of local players including Buttrey, McCoy, Drake, guitarists Kelton D. Herston, Norman Blake, Wayne Moss, and Charlie Daniels, and pianist Bob Wilson.

Opening the Nashville Skyline tracks recorded on February 13 and 14, 1969 is the first, surprisingly persuasive take of "I Threw It All Away." Dylan beautifully embraced more sophisticated songcraft with this composition, even to the point of writing a bridge (as he did on numerous Nashville Skyline songs). Take 1 of "To Be Alone with You" is rougher and more rollicking than the finished version, while Take 2 of "Lay, Lady Lay" reveals the ballad in sparse form. A more tentative Dylan is still working out his phrasing; Pete Drake's weeping steel guitar is absent as is Kenny Buttrey's offbeat percussion of bongos and cowbell that would become a significant characteristic of the recording. (Buttrey would play them on the verses and switch to drums for the bridge; it was a young studio gofer named Kris Kristofferson who was holding up the instruments for Buttrey to play!)  Bob Wilson's organ is also present, though much less prominent than on the LP version.

The relaxed meditation on a lost love, "One More Night," is considerably busier on Take 2. Dylan and Johnston knew when to slim down a song and when to beef one up (see "Lay, Lady, Lay"). The lone album outtake, "Western Road," is a standard blues, with some tasty acoustic piano soloing from Wilson; Dylan largely eschewed his "croon" on it, as well. It makes for intriguing listening, but it's easy to see why it was dropped from the final track listing. The sweet ode to "Peggy Day" (with the cute if unsurprising refrain of "I'd love to spend the night with Peggy Day") showcases Drake's steel; he's featured on three of the alternate takes, also including "Tell Me That It Isn't True" and the loose, freewheeling boogie of "Country Pie."

On February 17, Dylan returned to Studio A. After cutting a trio of takes (none of which are heard here), Johnny Cash dropped in. After recording three duets, Dylan went home, and Johnston produced two songs for a Cash solo session. The next day, Dylan, Cash, and Johnston reconvened with members of Cash's legendary Tennessee Three: guitarist Bob Wootton, bassist Marshall Grant, and W.S. Holland. Carl Perkins, who was then touring with Cash, also participated. Travelin' Thru marks the first authorized release of these oft-bootlegged sessions in stellar, you-are-there sound quality.

Dylan and Cash's camaraderie and mutual good humor is powerfully evident throughout these tracks, even though there's little doubt elder statesman Cash was in the driver's seat. (Johnston seemed content to largely leave the two talents and their band alone.)  There's some evidence supporting the theory that Dylan and Cash were recording with an album in mind: they recorded multiple takes of certain songs, Cash continually requested written lyrics (which seemingly never arrived), and so on. Dylan said as much in a contemporary Rolling Stone interview, while Cash asserted that he was only invited as a guest for his friend's new project. But whatever the reason for the session, it failed to produce much in the way of releasable material. It's easy to see why only the beautifully tender "Girl from the North Country" was deemed suitable at the time. That isn't to say, however, that their collaboration didn't yield enjoyable results.

Dylan added an uneasy harmony on the February 17 take of Cash's classic "I Still Miss Someone" with its unmistakable chick-a-boom rhythm. Their second take on the 18th turned out to be less ramshackle, but the crooning Dylan couldn't match Cash's deep, earthy baritone for gravitas. Still, the duet offers a hint of what might have been; like their version of "One Too Many Mornings" (Take 3, from February 18) with Dylan singing at his best, it would likely have worked with just a bit more polish applied and a real, rather than improvised, "head" arrangement.

Still more fascinating is the rehearsal/work session of "Don't Think Twice, It's All Right/Understand Your Man." Both the former by Dylan and the latter by Cash were based on the same traditional melody ['Who's Gonna Buy Your Chickens When I'm Gone"], and Cash was inspired by Dylan to write his version. Midway through, the two members of the mutual admiration society switched songs; Cash sounds touched that Dylan knew the words to "Understand Your Man." Again, with a bit of honing, the medley would likely have succeeded as a quodlibet in which each lyric was introduced first, and then Dylan and Cash sang the unique lyrics simultaneously. Without the introduction of each song, the simultaneous singing is messy but compellingly so - a moving union of two remarkable artists at their peaks.

A number of oldies were tackled at the sessions. Bascom Lamar Lunsford and Scott Wiseman's Appalachian folk song "Mountain Dew" inspired a couple of fun takes. Of more contemporary vintage, Cash revisited his Sun Records days with good-timey romps through his own "I Walk the Line" and Carl Perkins' "Matchbox" featuring Perkins on blazing guitar. The spirited cover of Arthur Crudup's "That's All Right, Mama," Elvis Presley's debut single, has a ragged charm that's infectious.  The "Mystery Train/This Train Is Bound for Glory" medley was less of an ideal fit, with forgotten lyrics leading to the take's demise.

Dylan added his harmony part to the choruses of the Cash-led "You Are My Sunshine" and "Ring of Fire." Chief among the pleasures of this set is hearing Cash "direct" the proceedings, such as on "Ring" when he suggests how he and his singing partner should split the lyrics. June Carter Cash was in the control booth, prompting her husband to seek her approval.  She lovingly reminded him to learn "Wanted Man," the song which Dylan had gifted him and which he would record just days later as the opening track of his At San Quentin live album.  The rough run-through here is another undisputed highlight as the singers struggle to finish it without laughter and with some seemingly improvised lyrics.

"What religious songs [do] you know, Bob?" Johnny asks with tape rolling as he and Dylan launch into rehearsing "Amen" and "Just a Closer Walk with Thee." A couple of charming Jimmie Rodgers medleys show their affection for the pioneering country artist, although neither Cash nor Dylan could credibly yodel in the style of The Singing Brakeman. Cash was a bit reticent to give the yodels a stab, but Dylan was game to try...at first!  While it would be difficult to compile these joint sessions into a proper album, the live-in-the-studio, fly-on-the-wall, warts-and-all documentary style here doesn't disappoint.

A trio of musical epilogues round out this Bootleg volume. First up is Dylan's performance from the June 7, 1969 broadcast of The Johnny Cash Show, recorded on May 1 at the venerable Ryman Auditorium in Nashville. Accompanied by many of the same musicians from Nashville Skyline (Blake, Daniels, Drake, Wilson, McCoy, and Buttrey), Dylan delivered strong renditions of "I Threw It All Away" and "Living the Blues" before joining the host to recreate "Girl from the North Country."

Originally planned as a single to coincide with the Cash broadcast, "Living the Blues" instead appeared on Dylan's controversial 1970 LP Self Portrait. Dylan recorded tracks for that crazy-quilt album while in Nashville for the taping, including two songs which remained unreleased until now (even eluding Bootleg Series Vol. 10: Another Self Portrait). The funked-up "Ring of Fire" has a far more confident vocal from Dylan than anything he recorded with Cash in the studio; he was similarly fiery if less believable on a high-octane treatment of his friend's "Folsom Prison Blues." He and the tight group of musicians had clearly hit their stride at that May 3 session, even if it remains Dylan's last in Nashville to date. Travelin' Thru concludes with four songs (two previously unreleased) recorded by Dylan and bluegrass titan Earl Scruggs on May 17 at the Carmel, New York home of Thomas B. Allen for a PBS special on Scruggs. Sonically, these tracks bear little relation to the Nashville recordings, but they function as a kind of coda to this journey through Dylan Country.

Packaging designed by Geoff Gans is top-notch as usual for The Bootleg Series releases. The thick booklet includes Ben Rollins' introduction, a comprehensive essay by country historian Colin Escott, and a heartfelt note from Rosanne Cash reflecting on the significance of Johnny Cash and Bob Dylan conferring esteem upon each other. The tracks have been mixed by Steve Addabbo and mastered by Addabbo and Mark Wilder, far outclassing any past unauthorized appearances.

Bob Dylan might have only been Travelin' Thru Nashville, but it was - by all accounts - a most memorable trip. This collection captures not only Dylan as he changed his voice and his songwriting style into something new but vividly brings to life the mutual respect he shared with another national treasure. Don't think twice about picking this one up...it's all right.

Travelin' Thru: The Bootleg Series Vol. 15 (1967-1969) is available now:

3CD: Amazon U.S. / Amazon U.K. / Amazon Canada
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