Singers Nick Ashford and Valerie Simpson, at the Washington Convention Center in Washington, DC August 7, 1989. (Harry Naltchayan/THE WASHINGTON POST)

She performed at the Star Plaza Theater near Chicago.

Simpson admitted the concert was difficult for her and didn’t perform certain songs like “Solid” and “Is It Still Good To You.” She told Jet Magazine she isn’t sure when she is going to perform another full concert.

In her interview with Jet: “It was tough having to sing those songs in their entirety alone. It was very emotional.” The show, headlined by The Whispers, had originally been booked with Ashford and Simpson as special guests. After her husband's death, says Simpson, "The promoter asked me to do it in tribute to Nick."

Ashford & Simpson were an iconic Motown singing duo and wrote hit songs for well-known artists like Ray Charles, Marvin Gaye and Diana Ross. Some of their most popular songs were “Ain’t No Mountain High Enough” and “Ain’t Nothing Like The Real Thing.”

Ashford told The Post in 1977: “We still don’t have a formula. I might think of a line or two. Valerie might hear me singing and try to catch up on the piano. But then I might hear her playing and come with an idea.”

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