Ross’ third film role came in The Wiz (October 1978). The Boss (May 1979) was a gold-selling album, followed by the platinum-selling Diana (May 1980) (the second of her solo albums with that name, though the other, a 1971 TV soundtrack, had an exclamation mark). It featured the number one single “Upside Down” and the Top Ten hit “I’m Coming Out.”
Ross scored a third Top Ten hit in 1980 singing the title theme from the movie It’s My Turn. She then scored the biggest hit of her career with another movie theme, duetting with Lionel Richieon “Endless Love” (June 1981). It was her last big hit on Motown; after more than 20 years, she decamped for RCA. She was rewarded immediately with a million-selling album, titled after her remake of the old Frankie Lymon and the Teenagers hit, “Why Do Fools Fall in Love,” which became her next Top Ten hit. The album also included the Top Ten hit “Mirror, Mirror.”
Silk Electric (October 1982) was a gold-seller, featuring the Top Ten hit “Muscles,” written and produced by Michael Jackson, and Swept Away (September 1984) was another successful album, containing the hit “Missing You,” but Rosshad trouble selling records in the second half of the 1980s. By 1989, she had returned to Motown, and by 1993 was turning more to pop standards, notably on the concert album Diana Ross Live: The Lady Sings…Jazz & Blues, Stolen Moments (April 1993).
Motown released a four-CD/cassette box set retrospective, Forever Diana, in October 1993, and the singer published her autobiography in 1994. Take Me Higher followed a year later, and in 1999 she returned with Every Day Is a New Day. Arriving in 2000, Gift of Love was promoted by a concert tour featuring the Supremes, although neither Mary Wilson nor Cindy Birdsong appeared — their roles were instead assumed by singers Lynda Laurence and Scherrie Payne, neither of whom had ever performed with Ross during the group’s glory days.
In 2006 Motown finally released Ross’ lost album Blue, a collection of standards originally intended as the follow-up to Lady Sings the Blues. The album I Love You from 2007 featured new interpretations of familiar love songs. That year, her contributions to the performing arts were acknowledged at the annual Kennedy Center Honors, and BET honored her with a Lifetime Achievement Award. Over the course of the following decade, she toured regularly and held a residency at The Venetian in Las Vegas. President Obama awarded her with the Presidential Medal of Freedom in 2016. All the while, Motown issued a handful of Ross anthologies, most notably Diamond Diana: The Legacy Collection.