An unflagging country radio fixture at 57, George Strait seems to have settled into a certain casual adventurousness. He opens Twang saying he's open to all kinds of music, then proves it: covering a Delbert McClinton soul rocker, trying on some greasy-spooned Louisiana R&B and an almost old-timey murder ballad; crooning a pair of smoky saloon songs whose relaxed jazziness recalls Alan Jackson's Like Red on a Rose; then finally closing with the Spanish ranchero "El Rey," written by Mexican legend Jose Alfredo Jimenez. Who says you can't teach an old traditionalist new tricks?