Fourteen years ago, the music world went a little overboard in celebration of what would have been Cole Porter’s 100th birthday. This year it’s Harold Arlen’s turn, and the tributes are pouring in. Likely to get buried beneath such higher-profile salutes as Concord’s double-disc Harold Arlen Centennial Celebration and Verve’s similarly titled Get Happy: The Harold Arlen Centennial Celebration, is Tom Wopat’s comparatively low-key, yet no less loving or lovely, Sings Harold Arlen: Dissertation on the State of Bliss (Sindrome). The former good ol’ boy, who’s made an estimable ascension from The Dukes of Hazzard to a string of Broadway musical revivals, remains a favorite among the New York cabaret crowd, but has yet to gain the mainstream attention he’s so long deserved. Sounding like a slightly gruffer Nat Cole with a dash of Sammy Davis Jr., Wopat handles a dozen Arlen tunes, ranging from the expected (“Over the Rainbow,” “Accentuate the Positive”) to the obscure (the wonderfully tender “Look Who’s Been Dreaming” and the cunningly sage title track), with unerring skill and marvelous intelligence.