Bob Dylan, "Another Self Portrait (1969-1971): The Bootleg Series Vol. 10" (Columbia)

In the latest entry of his ongoing vault-diving releases, Bob Dylan revisits one of his least-heralded albums. "Self Portrait," released in 1970, is remembered less today for its music than the classic first line of a Rolling Stone magazine review by Greil Marcus that greeted it: "What is this (expletive)?"

It was hard not to see why. The cultural icon baffled his fans with a badly-produced collection of minor compositions, some live cuts, covers of traditional folk and blues songs and even contemporary songs like "The Boxer." Marcus, who writes the liner notes for this four-disc box set, wisely doesn't step back from that assessment. He shouldn't. Time doesn't improve the work.

It seems amazing four decades later that an artist of Dylan's caliber would take such a hands-off attitude toward his art, packing up his basic tracks and sending them to a Nashville producer who adds some truly cringe-worthy arrangements. Maybe that was precisely the point.

Two of the discs in this box are primarily Dylan's original recordings with several outtakes, most with minimal arrangements. They're almost uniformly better than what was on the original "Self Portrait." There are a handful of interesting curios: a version of "If Not for You" with a haunting violin accompaniment, an unreleased studio session with George Harrison and a full band version of "I Threw It All Away."

Disc three is a recording of the 1969 concert at the Isle of Wight festival, which interrupted a period of seclusion for Dylan. Hard to go wrong with a recording of Dylan performing with The Band, but the performance has a tentative, almost rushed feel to it.

Although the "Self Portrait" sessions seemed strange at the time, Dylan's subsequent work gives it more context. Still performing regularly at 72, Dylan's concerts keep his formidable catalogue alive along with an American blues, rock and folk tradition that predates even him. These 1970 recordings make clear that even back then, Dylan was constantly inspired by it.

Marcus has another theory to explain "Self Portrait," suggesting it was Dylan's attempt to step away from people who worshipped him as a musical genius, a voice of his generation. "He was trying to quit, but no one would accept his resignation," he wrote.

Fine. So why would anyone want to buy a four-disc resignation statement? Through the years, Dylan's bootleg series has provided some real thrills, and interesting new perspectives on his work. This one doesn't. Only completists will find something interesting.