If it sometimes seems as if Willie uses a spinning wheel to pick which genre he’ll tackle next, American Classic finds the needle landing on a familiar spot: pop standards of the sort he first covered on the best-selling album of his career to date, 1978’s Stardust. American Classic is more lush and traditional than its predecessor, and the 31-years-later age and wear in Willie’s voice lend poignancy to a devotional like “Come Rain or Come Shine.” But romantic duets with jazz singers Diana Krall and Norah Jones—31 years and 46 years Willie’s junior, respectively—fall prey to uncomfortably mismatched casting.