by Stephen Thompson Bringing blues music to the Top 40 isn't easy: Only a handful of musicians have done it in the 30 years Robert Cray has spent winning awards, selling millions of records and otherwise kicking around on the national stage. But Cray has, crossing over from blues-club stages to arenas with the double-platinum 1986 album Strong Persuader and its single "Smoking Gun," and has continued to stick around as one of the most reliably gifted and accessible guitarists around. For all the attention Cray receives as an instrumentalist, it's his smooth, smoky voice that really sells his music. Equal parts soul man and blues belter, he presides over a crack band — bassist Richard Cousins, keyboardist Jim Pugh and drummer Tony Braunagel, who performs here by tapping a wooden box — at this Tiny Desk Concert in the NPR Music offices. Like any great blues singer, Cray makes heartache and other romantic dysfunction sound engaging and relatable: Ironically, if not surprisingly, his saddest song here (yes, sadder than "Sadder Days") is the one called "I'm Done Crying." But all three of these tracks, culled from Cray's new album Nothin But Love, execute the deftest possible blend of emotional misery and instrumental majesty — just the way the blues ought to be.