The last albums great singers labor over before they die share an eerie quality — their voices retain depth and richness, but they substitute weariness for power. Like Alzheimer’s-afflicted Glen Campbell or cancer-stricken Leonard Cohen over the past year, Gregg Allman, who died at 69 in May, must have known the time was near, as he canceled 2016 concerts due to illness around the time he was laying down vocals for “Southern Blood” (Rounder). This sad acknowledgment haunts his solo album of mostly covers: “I can’t tell my pillow from a stone,” he sings on the Grateful Dead’s “Black Muddy River”; “I don’t really care what happens next,” he adds on Bob Dylan’s “Going Going Gone.”

The former Allman Brothers Band frontman’s famously gnarled vocals fit beautifully with a sympathetic band and gospel harmonies on Little Feat’s “Willin’” and his own “My Only True Friend.” He lacks the sharp hunger of early Allmans classics or the blissed-out soul of his recent work, but “Southern Blood” has a lean, bluesy persistence, especially on “Song for Adam” (with Jackson Browne) or Jack Avery’s spooky “Blind Bats and Swamp Rats,” which Johnny Jenkins recorded in 1970 with Allman’s late brother, Duane, on guitar.