When writer Toni Morrison said that black artists always seem to move with ease, she was talking about someone like Al Green. He sings from the side of his mouth, seemingly straight from the heart — his every sigh, mutter, trill and moan worth 100 twenty-dollar words — yet it seems like he’s just being Al. Which isn’t to say that 1973’s Call Me, now remastered to full luster, isn’t about amazing singing, from phenomenal falsetto hollers to deep-throated innuendoes. Green delivers the seductive come-on “You Ought to Be With Me” with the righteousness of a holy man, and in “Jesus Is Waiting,” he cries out like a man trapped in an ecstatic experience that’s both spiritual and carnal. Explores Your Mind is earthier: The great soul singer revels in zipperless sex (the almost whimsical “One Nite Stand”) and longs for innocence (the doo-wop-haunted “School Days”). The most poignant moment is “The City,” wherein Green, who in 1974 was already quite world-weary, rapturously describes the bright lights and fame awaiting him in a distant metropolis. When he was singing about it, even ambition sounded like an act of faith.