14 behind-the-scenes photos showing Bob Dylan joking around with his famous friends backstage

Rehearsals began in early October 1975 in New York City.

The Rolling Thunder tour was different from Dylan's previous in that he invited many musicians to tour with him, including The Byrds' lead singer Roger McGuinn, Joni Mitchell, T-Bone Burnett, Mick Ronson, and others.

Regan is quoted in the foreword of his book: "Bob had given me free rein to shoot it all — onstage, offstage, dressing rooms, parties, trailers, whatever was going on."

Because of this unrestricted access, Regan was able to capture intimate moments between Dylan and many of his close friends, including this one of Patti Smith. Regan found them on the stairwell while at a party in Greenwich Village in New York City.

Before heading out on tour, Dylan stopped off at the Secret Sound Studios in Manhattan to record a duet version of the song "Buckets of Rain" with Better Milder for her album "Songs of the New Depression".

Regan shot almost 14,000 photos during his time with Dylan.

During some of the shows, Dylan chose to wear white face paint. "I want the people way in the back to be able to see my eyes," Dylan explained to Regan.

The first leg of the tour stopped in 23 cities, starting in Plymouth, Massachusetts, and ending at Madison Square Garden in New York City.

Here, Dylan plays at the home of folk singer Gordon Lightfoot (left) with Roger McGuinn (right).

While in Lowell, Massachusetts, in early November, Dylan paid his respects at Jack Kerouac's grave site.

When Dylan played New Haven, Connecticut on November 13, the already-famous Bruce Springsteen came backstage to say hi to Dylan.

At that same show, Regan captured what Dylan claims to be the best photograph anyone has ever taken of him. Regan is quoted in the new book: "He turned around and looked right at me. I caught his eye and asked him to hold it for a minute. It was more like thirty seconds." The image went unpublished for 27 years until it graced the cover of the live album "The Bootleg Series Vol. 5: Bob Dylan Live 1975, The Rolling Thunder Revue".

The final night of the first leg of the tour was at Madison Square Garden, and was a benefit concert held for imprisoned boxer Rubin Carter. It was known as "The Night of the Hurricane", and Muhammad Ali came to visit Dylan backstage. He delivered a gift: a huge boxing glove.

In the foreword of the book, Guy White writes, "Ken was the soul of discretion. He never talked in depth about his time on the tour — for good reason — he wanted his photographs to do the talking."