Few artists have enough quality outtakes to fill an entire album. An even smaller number of artists can round up enough leftovers to fill a four-disc box set that's almost as essential as other classics in their catalog.

Bob Dylan is one (see his ongoing Bootleg Series); Bruce Springsteen, whose Tracks collects 66 mostly unreleased songs from 1972 through 1995, is another.

The box set was released on Nov. 10, 1998, in between Springsteen's longest layover ever between albums: seven years from 1995's acoustic folk record The Ghost of Tom Joad until 2002's The Rising, the first album recorded with the E Street Band since 1984's Born in the U.S.A. Following a pair of coolly received albums in the early '90s and the uncharacteristically laid-back Tom Joad, fans needed a reminder exactly why Springsteen was so revered in the '70s and '80s.

They got it with Tracks.

Starting with 1978's Darkness on the Edge of Town, Springsteen famously started recording more songs than he knew what to do with. He gave some away. He put some on the flip sides of singles. And some he just tucked away in his vault. A huge bulk of those appear on Tracks, along with some early demos, a handful of live tracks and a more recent unused song that's revisited for the set.

It all paints a pretty thorough picture of Springsteen through the years – from the four demos from 1972 that were reworked on his debut album (and which owe a lot to Dylan) and the two Born to Run outtakes that were wisely cut from his breakthrough LP to the more than a dozen leftovers that didn't make the world-conquering Born in the U.S.A. and way too many unused songs from Human Touch, which was recorded without the E Street Band.

Listen to Bruce Springsteen's 'Linda Let Me Be the One'

Not surprisingly, the best songs here stem from sessions for Springsteen's best albums. "Thundercrack" (from The Wild, the Innocent & the E Street Shuffle), "Hearts of Stone" (a Darkness outtake given to Southside Johnny), "Be True" (a B-side from The River) and "Pink Cadillac" (a Born in the U.S.A.-era B-side) top the list, but there are plenty more that could have easily made it onto their respective LPs.

The project came together rather quickly, as Springsteen and engineer Toby Scott began sifting through more than 350 unreleased songs in early 1998 that the Boss had accumulated over the decades. For most of the year, they remixed the original recordings – which they had initially considered releasing in rough form – and pieced together some of the songs that needed additional instruments and tweaking.

By midyear they had collected and cleaned up 100 songs for Tracks, which was eventually whittled down to the more than five dozen that ended up on the four-CD box. A few were conspicuous in their absence, like early demos of cuts that didn't make Greetings From Asbury Park, N.J. and the band sessions that preceded the release of the solo acoustic Nebraska in 1982. (Six months later, a single-disc compilation, 18 Tracks, included three additional outtakes exclusive to that set.)

Later Springsteen boxes gathered more unreleased material: 2010's The Promise collects 21 additional outtakes from the Darkness on the Edge of Town sessions, and 2015's The Ties That Bind includes a single disc of leftover tracks from The River, including a few that are also on Tracks.

But those are tied to specific albums. Tracks spans his career, and in a way is a better overview of the wealth of great material that sat on the shelves for years. And like Dylan's celebrated Bootleg Series, Tracks serves as a companion to a great catalog as well as a work that stands independently as a significant part of that catalog.

20 Greatest Comeback Albums

Becoming a successful artist is difficult. Remaining on top forever is downright impossible.

Why Bruce Springsteen Called Killers Collaboration ‘Cathartic’

More From 96.7 The Eagle