Thirty-five years after writing “Mr. Soul,” Neil Young took that moniker at face value by recruiting Booker T. & The M.G.’s for a warm, romantic set steeped in ‘60s-Stax vibes. The knowing Temptations tribute that opens “You’re My Girl” telegraphs the album’s throwback mission in no uncertain terms, and even songs powered by Neil’s grungy guitar tone, like “Mr. Disappointment,” emit a churchly glow. However, on “Let’s Roll,” a Southern-boogie groove sets up a gripping narrative ripped straight from the 9/11 headlines.