Later, Ashford attended and graduated from Willow Run High School in Ypsilanti, Michigan, before pursuing his professional career, when he would ultimately meet his wife, Valerie Simpson.

They started their career in the mid-1960s, writing for artists such as the 5th Dimension ("California Soul"), Aretha Franklin ("Cry Like a Baby"), and Ray Charles ("Let's Go Get Stoned").

That was followed by several obscure singles recorded by Ashford on the Glover, Verve and ABC labels, such as "It Ain't Like That" (not the same song as they would later write for Martha Reeves and the Vandellas), "California Soul", and "Dead End Kids", backed by his own version of "Let's Go Get Stoned".

Simpson appeared (with Melba Moore) as part of the "Blood, Sweat & Tears Soul Chorus" on the band's debut album Child Is Father to the Man in 1968.

After concentrating on working with other artists, Simpson was the featured soloist on the songs "Bridge Over Troubled Water" and "What's Going On" on the Quincy Jones albums Gula Matari in 1970, and its follow-up, Smackwater Jack.

In 1975, Simpson sang backing vocals on Paul Simon's number-one hit "50 Ways to Leave Your Lover", and in 1976 they released Come As You Are.

On his own, Ashford (along with Frank Wilson) produced the hit "I'm Gonna Make You Love Me", which Diana Ross & the Supremes recorded in collaboration with the Temptations in 1968.

He also appeared in the movie New Jack City (1991), as Reverend Oates, an ordained minister who was part of Nino Brown's entourage.

On August 16, 2006, Playbill Online reported that they were writing the score for a musical based on E. Lynn Harris's novel Invisible Life.

[11] In January 2007, they, along with Tina Turner, Mary J. Blige, Mariah Carey, Sidney Poitier, director Spike Lee, and comedian Chris Rock accompanied Oprah Winfrey when she opened her Leadership Academy for Girls in South Africa.

The track is based on a sample of Marvin Gaye and Tammi Terrell's 1967 Motown hit "Ain't No Mountain High Enough".

Ashford died at the age of 70 in a New York City hospital on August 22, 2011, four days before Valerie Simpson's 65th birthday, of complications from throat cancer.

[12][13] Simpson released a solo album in June 2012, called Dinosaurs Are Coming Back Again, which also features the last recorded performance of Nina Simone, a second duet with Roberta Flack and an instrumental version of "Ain't No Mountain High Enough".