What Robert Earl Keen fans share in common with Bob Dylan and Kris Kristofferson fans — and there’s no reason to assume there’s not overlap between those groups — is a certain set of priorities. That is, the exalted quality of the songwriting — lyrics, in particular — ranks far above the technical limitations of the voices singing them. Keen, a native Texan, has a pinched, inelastic vocal timbre. But his songs, including several on this year’s Ready For Confetti, brim with skewed humor (“Who Do Man”), literary depth (“Black Baldy Stallion”) and humanistic empathy (“Lay Down My Brother”). And it’s no coincidence that he included a cover of East Nashvillian Todd Snider’s “Play a Train Song”; Snider is his like-minded, mutually admiring occasional tour mate. Opening this show is The Deep Dark Woods, a Canadian band whose multipart harmonies are more pristine than Gram Parsons and the Byrds might’ve dreamed possible.