Nikolas Ashford and his wife Valerie Simpson were a husband and wife duo with two careers: one as a successful writing and producing team and the other as singers and performers themselves. They started their career in the mid-1960s, writing for artists such as the 5th Dimension, Aretha Franklin and Ray Charles. At Motown they were paired with the vocal duo Marvin Gaye and Tammi Terrell, and they wrote and/or produced all but one of the late-1960s Gaye/Terrell singles. They also wrote and produced almost all the songs on three 1970s albums for former Supreme Diana Ross.

Ashford & Simpson's career as recording artists began in the early 1960s with the gospel group the Followers. In 1974, Ashford and Simpson married after resuming their career as a duo with the Warner Bros., and in 1975 Simpson sang backing vocals on Paul Simon’s number-one hit “50 Ways to Leave your Lover.” On his own, Ashford coproduced the hit “I’m Gonna Make You Love Me” recorded by Diana Ross & The Supremes. In January 2009, they released a CD and DVD of their live performances titled The Real Thing and in June, they made a guest performance at a party at Tribeca Rooftop, New York, to celebrate Virgin Atlantic's birthday party. They also made their first appearance in Tokyo, Japan, in November and performed eight shows in four days at Blue Note Tokyo.
At President Barack Obama's 2009 inauguration, Ashford and Simpson rewrote their song, "Solid", as "Solid as Barack". They dedicated it to him at his inaugural festivities.
The duo was inducted into the Songwriters Hall of Fame in 2002. Other awards include The Rhythm & Blues Foundation’s Pioneer Award, ASCAP Founders Award and the Grammy Trustee Award.
Ashford died in a New York City hospital in 2011 of complications from throat cancer.