Sound-wise, 1971’s Willie Nelson & Family is no different than the 11 studio albums that precede it: They are awash in the Countrypolitan sound, with strings, horns and backing singers. But the version of “Sunday Mornin’,” complete with its guitar solo — one of the first on Nelson’s legendary Trigger guitar — feels like the first act of defiance and a statement of intent. “If Kris Kristofferson can do this, I can do it too,” Nelson seemed to be saying. Within 18 months, he’d be in New York making Shotgun Willie, free to follow his muse wherever he went, cementing Kristofferson’s outlaw country jumpoff point. And that’s why Willie Nelson & Family is such an interesting artifact: It’s the last album Willie made in his “Before” timeline; it’s the point where he started putting it all together and asserting his creative ideas in tangible ways.