Picking the best song or songs written or co-written by the late Glenn Frey, who died Jan. 18, 2016, from complications from pneumonia and colitis, is a near-impossible task. It's like asking someone what their favorite body part is — there are many, many great choices, few wrong ones, and making a definite decision could drive any number of music fans to distraction. But Frey's legacy is that of a peerless songwriter and vocalist, one who spent much of the 1970s atop the charts and entertaining legions of fans around the world, but also managing to find a way to write genuine,...