Diana Ross’ meticulously considered solo debut features the utterly human love songs of R&B songwriting powerhouses Nickolas Ashford and Valerie Simpson. They turned out to be an ideal match; Ross brings a determined yet gentle performance on ”Ain’t No Mountain High Enough,” while the soft sway of “Where There Was Darkness” culminates in joy. Lush arrangements, like the swooping strings and backing vocals that circle her on “You’re All I Need to Get By,” only make Ross’ presence that much more towering.