Diana Ross had just left her post as lead singer of The Supremes (the final Supremes single with Ross was the stunning “Someday We’ll Be Together”) and signed a solo deal with Motown Records when she released this 1970 debut. If Motown had ever been nervous about one of its stars not reaching predicted heights, this was it. But said fears were unfounded: the songwriting team of Nick Ashford and Valerie Simpson penned (and produced) most of the album, which included Ross’ first solo No. 1 hit, the incredible “Ain’t No Mountain High Enough” (first recorded in 1966 by Marvin Gaye and Tammi Terrell). Indeed, this string-heavy collection is rich with other stellar songs and highlights, including the Supremes-y “These Things Will Keep Me Loving You” and the tender “Now That There’s You.” The added bonus tracks are a treasure, unearthing some pre-album work Ross did with other producers and writers, including two telling Laura Nyro covers (“Stoney End” and the should’ve-been-huge “Time and Love”), as well as a left-turn Jimmy Webb song called “The Interim,” an experiment that mixed Motown’s pop soul with singer/songwriter Los Angeles.