Simpson, who penned hits for Chaka Khan, Diana Ross, Whitney Houston and others will be inducted into the Women Songwriters Hall of Fame on June 25 at an awards ceremony in Washington, D.C.
Valerie Simpson
Valerie Simpson
| Credit: Rodin Eckenroth/FilmMagic

One day, over four decades ago at their home in Westport, Connecticut, Valerie Simpson and her songwriting partner and husband Nick Ashford were working on a song for Chaka Khan when Nick came up with the iconic line "I'm Every Woman."

"I told him to dig into his feminine side," Simpson tells PEOPLE. "I knew immediately it was a great title, which he got from me playing the chord [on the piano]. It was one of those things that just all came together."

The song "I'm Every Woman" would become a No. 1 hit for Khan in 1978, and later for Whitney Houston. "That song," says Simpson, "became very much a woman's anthem. With Chaka, she just is like a dynamo, unstoppable, very sexy person. Her persona is just all woman, which is why she did "I'm Every Woman" so well."

Valerie Simpson; Nickolas Ashford
Valerie Simpson and Nick Ashford
| Credit: CLINT SPAULDING/Patrick McMullan via Getty Images

On June 25, Simpson will be inducted into the Women Songwriters Hall of Fame, along with nine other inaugural inductees: Roberta Flack, Tawatha Agee, Mary Chapin Carpenter, Naomi Judd, Deneice Williams, Dawnn Lewis, Klymaxx, Dr. Veryl Howard, Bunny Hull and Jekalyn Carr.

Simpson and Ashford — who died in 2011 — co-wrote multiple classic Motown hits, including "Ain't Nothing Like the Real Thing," "and "Ain't No Mountain High Enough," a romantic song from 1967 written for Marvin Gaye and Tammi Terrell. 

After Diana Ross left the Supremes in 1970, Ashford & Simpson were put in charge of producing Ross' debut solo album -- featuring the singer's No. 1 hit version of  "Ain't No Mountain High Enough." 

"It was a great honor," says Simpson. "It was almost like she had to redefine herself. And so, you want to give her a voice that is different from the one she's had with the two girls, singing with the Supremes." 

When Whitney Houston re-recorded 'I'm Every Woman' in 1992, Simpson describes Houston's rendition as taking the song "so much further than you could ever imagine — she gave it wings," she says. "Her voice was just spectacular. Any songwriter, you want a vehicle that can carry your song beyond itself, and she had that kind of voice."

Simpson knew Houston prior to the singer's descent into a much-publicized drug addiction; when she died in 2012 from accidental drowning, Houston was found to have cocaine in her system.

"I knew her through good times," says Simpson. "She'd come to my house in Connecticut. We had Fourth of July. We called them the white parties, everybody dressed in white, and she'd come and wear her white and judge whatever competition we had going on."

"I see her through fun times and that's my memory of her," Simpson continues. "She died young, but she lived more in her life than the average person."

Nickolas Ashford; Valerie Simpson
Nick Ashford and Valerie Simpson
| Credit: DAVID X PRUTTING/Patrick McMullan via Getty Images

Decades after Houston's rendition of "Ain't No Mountain High Enough," the song lives on, recently covered by R&B singer Tinashe. "That's the beauty of a great song; they take wings of their own," says Simpson. "So many people find their own reason to love it."

In the years since Nick's death at 70 years old, Simpson has been writing lyrics solo and in 2018 made her Broadway acting debut in Chicago in the role of Matron "Mama" Morton.

"I remember opening night, it was scary," she says.  "I felt like I wanted to run off the stage and  jump in my car and go home. But I got through it. I walked on."

As for future projects, Simpson has been asked to "write my life as a theater piece" as a musical, which she calls "exciting, but scary."

"But that's what life is about. Life is about new moments," she says. "I stay open to life. I think that's what has to happen if you're going to move forward. Things change and you have to change with them."

The 2021 Women Songwriters Hall of Fame awards show will be held June 25 at the National Museum of Women in the Arts in Washington, D.C., at 4:30 p.m. Tickets for the event are available here.