Nickolas Ashford of the legendary songwriting team Ashford and Simpson died Monday from complications of throat cancer in a New York hospital. He was a young 69.

Ashford, who recorded and performed professionally with his wife of 30+ years, Valerie Simpson, is best known for writing the 1984 hit songs “Solid (As A Rock)” and 1967’s “Ain’t No Mountain High Enough” recorded by Marvin Gaye and Tammi Terrell.

Ashford and Simpson never reached the heights of fame as the superstars who recorded their musical compositions, such as Diana Ross, Chaka Khan and Marvin Gaye. But Ashford, who was reportedly bisexual, will be remembered for his classic R&B hit songs, his falsetto voice, his flamboyant long flowing hair and his colored eye contact lenses that set him apart from other male R&B performers of his era.

Ashford and Simpson, who were married 37 years, have two daughters, Nicole, 35, and Asia, 23. In an interview with SFGate.com, Ashford and Simpson explained the keys to a successful marriage.

“I think the key to our case is the eight years we weren’t married,” Simpson says. “That defined our roles. We can always go back to that place mentally – get past the husband-wife stuff and go to ‘songwriter,’ ” said Simpson.

“You’ve got to keep talking,” added her husband.

“And lots of laughs,” she says. “You’ve got to keep laughing.”

“And have as much sex as possible,” said Nick.

“Even if you have to schedule it,” said Simpson.

Nick Ashford spent several months in the 1960s homeless and sleeping on park benches. To remind others of his long, arduous journey to the top, Valerie Simpson bought a bench in midtown’s Bryant Park and inscribed the plaque, “Nick Ashford Slept Here.”