The rousing and arousing musical partnership of Al Green and producer Willie Mitchell in the Seventies was built around the high art of the lowdown groove. Yet it took these two soul giants a bit of time to rediscover their own groove. I Can’t Stop — their 2003 comeback collaboration — was impressive, but something was missing. It was as if Reverend Al was dipping the hem of his garment into the secular waters without allowing himself to get too wet or too turned on by his own sensual gifts. Everything’s OK is something else entirely: This time the flesh and the spirit are both willing and the tunes top-notch, especially standouts like “Build Me Up” and the appropriately affirmative title track, both written and produced by Green and Mitchell. There’s also one of those classic Green covers where the Rev shows his stylistic flair for reinvention — a characteristically expressionist version of “You Are So Beautiful” that Joe Cocker could hurt himself attempting to replicate. Recorded last summer in Memphis, Everything’s OK is much more than OK — it’s one more righteous, red-hot reason to treasure this surviving genius of soul.