The above gallery of Top 10 "Leftovers" Albums finds some of rock's biggest acts -- from Led Zeppelin to Bob Dylan to Bruce Springsteen -- digging into their vaults in order to put together new records filled with songs left unfinished or unreleased from previous projects.

Although the idea of combing through one's archives is often seen as a cash-grab, the re-heated audio meals found in the gallery above have a genuine purpose. For some of the artists, they arrived in moments of creative inertia or deep sadness following breakups or even deaths. For others, they served as placeholders, allowing the groups to have something for their label to release in time for a tour – or while they work on, say, a movie or an all-new album that's taking a little longer to complete than expected. And in a couple of cases, they provided valuable looks at alternate career paths that could have been taken.

As such, these closet-cleaning efforts often lack the quality, cohesiveness and focus of a traditional "new" release. And while that can lead to disappointment on first hearing them, over time they have come to be valued – and in some cases, essential – parts of the artists' catalogs. We think that all of the entries in the above gallery of Top 10 "Leftovers" Albums fall into the latter category, either as testaments to what came before or as individual statements in their own right. Click on the image above to begin.

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