Conceived of in a dream and sketched out during a series of pre-dawn sessions before the talons of logic took hold, Seven Psalms is a frankly mysterious album that nevertheless finds its way back to the same thematic wells Simon has drawn on for more than 50 years: loneliness (“Trail of Volcanoes”), aging (“Wait”), the existential questions of ordinary people (“The Sacred Harp”), and the sense of humor that keeps them gently at bay (“My Professional Opinion”). With an arsenal of rustling percussion and eerily resonant bells to back up a lone acoustic guitar, he plays the role of the solitary man haunted by a history of voices. And while the music is rarely catchy (at least for someone who wrote “Cecilia”), it continually refers back to itself with a subtle magic that honors the places from which it came. He’s always played it close to the vest; here, he’s deep inside it.