Seventy-three-year-old cowboy Willie Nelson has had his share of hits and misses and some folks have even dared to question his relevance and place in the tomes of musical history. But no one survives in this industry without strong material and even stronger alliances. Thankfully, Nelson has an abundance of both. From the opening drawl of “Rainy Day Blues” to the off-minor lament of “Amazing Grace,” the brilliant production and guitar work of Ryan Adams brings a richly ragged edge to the Texas troubadour’s soft swagger. Often dark, and even haunting, Songbird is chockful o’steel-pedal soul, gospel glory and the stuff that legends are made of.