In the post-Johnny Cash-Rick Rubin music world, oddball aging-rocker reinventions are no longer risky — they’re often a necessity if middle-aged stars want to shake the has-been label. In Robert Plant’s case, in addition to padding his wallet with Led Zeppelin reunion dollars, the singer has decided to chase more artistic pursuits by teaming up with bluegrass darling Alison Kraus and celeb producer T Bone Burnett. While the resulting album isn’t a knockout, Plant and Krauss do manage to move beyond the realm of novelty.

In fact, Raising Sand is probably the most tasteful album of Plant’s career (mind you, he did largely build his fortune singing about his genitals). Krauss and Plant slide through a selection of well-chosen covers, including lesser-known songs by Gene Clark, Tom Waits and Townes Van Zandt. Surprisingly, Plant doesn’t dominate — if anything, his voice (which is so soft that it’s barely recognizable) supports and blends into Krauss’s. Raising Sand’s big flaw isn’t that Plant seems out of place. It’s that he doesn’t stand out enough. Burnett’s production definitely pushes the album into the category of Starbucks rock — even as Plant and Kraus drift into country and Everly Brothers territory, the tempo remains steady and dull. It’s nice to see that Plant can play grown-up, but at this rate he may as well be playing dead.