A deeper look at the grooves pressed into the Exit Stencil reissue of the Sings Blues and Hymns LP by Cat-Iron. In my life, I have had three perception-altering experiences with the blues. The first was when I heard Howlin’ Wolf; when I first heard the moans and growls which came off songs like “Smokestack Lightning,” it rattled me to the core and hooked me with the inherent danger of it. The second time the blues changed my life was...