(CNN) -- Next to Beyonce, the musical surprise of the 2013 holiday shopping season so far is the limited iTunes release of "The Beatles Bootleg Recordings 1963." It's a potential gold-mine excavation: fifty-nine previously obscure tracks, unknown outside the subculture of obsessive collectors. Over on the bookshelves, the recently published first volume of biographer Mark Lewisohn's three-part "The Beatles: All These Years" takes up considerable space. Titled "Tune In," the first book offers 944 pages on the iconic group, concluding in 1962 -- before they were famous. Beyond serving as baby boomer stocking stuffers, do these kinds of archaeological digs enhance the Beatles' legacy? Or is pop-culture nostalgia starting to scrape the bottom of the barrel?
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Mark Coleman: "Bootleg," a release of obscure Beatles tracks, is a holiday surprise
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He says group still earns millions and release may be tied to extending copyright
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With new 944-page book, too, he asks if Beatlemania is scraping dregs of barrel?
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Coleman: Some leftovers can be appetizing such as Dylan's recent "Bootleg Series" release
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It's hard to imagine the retrieved versions replacing the originals in anyone's affections, but casual fans should be entranced by the behind-the curtains glimpses into the early @placeholder working process.