Bob Dylan's latest collection of material from his musical back pages, "Tell Tale Signs: The Bootleg Series Vol. 8," is a rich, revealing look at how this master songwriter put together one of the most dramatic creative renaissances in pop history.

When Dylan set aside his songwriting in the early 1990s to record two albums of vintage folk, country and blues tunes, many fans thought his long, remarkable career was nearing an end. As we have since learned, Dylan was just returning in those albums to musical traditions that felt more honest to him.

After reconnecting with those rural, pre-rock styles, a rejuvenated Dylan surprised the doubters with a brilliant series of works that began in 1997 with the deeply introspective, Grammy-winning "Time Out of Mind" and continued with the more playful and jubilant "Love and Theft" in 2001 and the wry, majestic "Modern Times" in 2006.

Listening to the rare and unreleased material from the last two decades in "Tell Tale Signs," we can hear Dylan reaching for and regaining the spark. Whether he's simply interpreting traditional numbers or writing new songs, he brings such passion and intimacy to his vocals and arrangements that the line between singer and writer is blurred.

The highlights include a marvelous, never-released Dylan song that was recorded during the sessions for "Time Out of Mind" and his versions of two songs by landmark influences: country singer Jimmie Rodgers' "Miss the Mississippi" and bluesman Robert Johnson's "32-20 Blues."

Dylan is such a big Rodgers fan that a few years ago he got Bono, Van Morrison and others to join in a tribute album to the man who is often called the father of commercial country music, but this is the first time he has released one of his own versions of a Johnson song. In both cases, you can sense Dylan's deep respect for the artists and their respective musical forms.

The new collection will be released Oct. 7 in a standard two-disc set that contains 27 songs and in a deluxe three-disc set that offers 12 additional tracks and other features. As of today, the songs on the two-disc set are being streamed free on National Public Radio's website until the sets go on sale.

The back story: There were so many twists and turns on Dylan's road to creative recovery that most of us will need a program to tell what is going on in this collection. Larry Ratso Sloman, who has written a book on Dylan, contributes liner notes that serve as the perfect guide.

In the various songs here, Dylan still deals with themes of struggle and faith, despair and hope, but his singing and the musical textures are tied to the vintage sounds that thrilled him as a youngster in Minnesota before he began his own musical journey.

On one hand, the music here could exist even if rock 'n' roll never happened, but it's difficult to think of rock 'n' roll without the passion and attitude of these tunes.

The music: The first disc opens with one of the deluxe set's three previously unreleased versions of "Mississippi," a Dylan song from the "Time Out of Mind" sessions that first appeared on "Love and Theft."

In the first, Dylan's vocal is gentle and reflective, and he's backed only by producer Daniel Lanois' guitar.

On the second, he's joined by the band, and the effect is more formal.

On the third attempt, he experiments with different lyrics. None is even close to the brighter treatment that was finally released. Thanks to these and other live or alternative versions of songs, we get a valuable glimpse into Dylan's method of constantly testing a song's various options.

The best of the new Dylan songs is "Red River Shore," a drastic, 7 1/2 -minute reworking of a traditional tune recorded years ago by the Kingston Trio. The opening line suggests the song's epic reach: "Some of us turn off the lights and we live / In the moonlight shooting by / Some of us scare ourselves to death in the dark / To be where the angels fly."

The tension and drama of the tale of longing and loss don't let up until the final verse, in which we learn that the woman of the narrator's dreams has slipped from his life. The loss is so deep that the narrator tries to dust off his faith. He tells of hearing about a God who could bring the dead back to life, and he ends up wondering if "they do that kind of thing anymore."

"Tell Tale Signs" is not just "extra" Dylan. It's essential Dylan.