An underappreciated part of Bob Dylan's career

Van Morrison Bob Dylan Robbie Robertson last waltz
Van Morrison, Bob Dylan and The Band's Robbie Robertson (from left to right) onstage in 1976. The performance was filmed for Martin Scorsese's "The Last Waltz."
United Artists | Getty Images 1976

The latest installment in Bob Dylan's Bootleg Series is due out Friday.

Volume 13 covers Dylan's born-again Christian period from 1979 to 1981.

The eight-CD set includes outtakes and spirited live performances.

During that era, Dylan shows featured none of his hits, only the gospel songs. He also delivered full-fledged sermons.

Clinton Heylin is writing a book about this period. He argues that it's a misunderstood and underrated part of Dylan's career.