The Devil has gotten too greedy. Time was, if mortals wanted musical fame, all they had to do was relinquish their immortal souls. But lately, the Dark Lord has added a new clause to his time-tested showbiz contract. In addition to eternal damnation, aspiring stars must also vow to make an album of one (or more) of the following: cheesy duets, jazz standards, or cover versions. Seriously, who else but Satan could claim responsibility for Erasure interpreting the Righteous Brothers?

But singer, songwriter, and guitarist Slaid Cleaves—who plays the Triple Door on Wednesday, June 21—just pulled a fast one on Mephistopheles. Yes, all the material on his fourth full-length, Unsung (on Rounder), comes courtesy of other composers. But the Austin, Texas, resident ensured his selections would sound fresh, regardless, by limiting his choices exclusively to work by little-known peers.

These 13 songs may be unfamiliar, but Cleaves renders them memorably. "Everette," a bittersweet Steve Brooks ditty, struts along to a jaunty beat that belies the lyrical undercurrent of disillusionment. On "Flowered Dresses," penned by one of Cleaves's favorites, Karen Poston (he included her song "Lydia" on the 2000 album Broke Down), piano and cello accent his depiction of a pretty heroine slowly fading away, like the upholstery on a sofa left in direct sunlight too long.

What doesn't appear on Unsung defines it almost as much as what does. For example, Cleaves initially considered including "Ride On," from Dirty Deeds Done Dirt Cheap. "It's a very lonely, depressed, picture of life on the road. Any folk singer could do it," he observes. "But I'm doing songs from my community... and since I don't know anyone in AC/DC, it didn't really fit the theme."

Mary Gauthier, who sings backup on Unsung, was excluded for different reasons. Cleaves has been her fan, and friend, for several years. "I was running sound at an open-mic gig when she showed up in Austin for the first time," he recalls. "She did two songs and she blew me away. She stood out above all the other performers that night... that whole year, in fact."

But because Gauthier, who made her major-label debut last year with the critically acclaimed Mercy Now, is increasingly well-known, Cleaves bypassed her catalog. "There were several others I could have gone to for material, like Eliza Gilkyson or Ray Wylie Hubbard, but they didn't quite fit. The purpose of Unsung was to present these songs as if they were my own, because nobody has ever heard them." When he first started busking on New England sidewalks, Cleaves steadfastly refused to play James Taylor or adult-contemporary favorites; he isn't about to change his tune now.

With Unsung, Cleaves has achieved the almost unthinkable: making a album of covers that equals, and sometimes even outshines, his originals. Crafty. Satan is undoubtedly pissed. But at this rate, Cleaves might even discover a loophole that allows him to achieve earthly fame and still slip into Heaven.