"They thought we needed some different exposure". Nick Ashford blurted out, explaining why he and Valerie Simpson, his partner in songwriting, producing, performing and living, are appearing with Boz Scaggs at the Merriweather Post Pavilion this week.

Simpson quickly interrupts. "No, it just was't they. It was a joint decision," she amended, as Ashford smiled. "We have been playing to a 70-30 black to white audience. And we are just doing what should come next, trying to attract a larger house, trying to reach an audience that's half black and white."

Any personal frustration is vigorously denied. "It's very natural to want to grow", said Simpson, her tiny legs tucked under her brown and white seersucker shorts. Both have shoulder-length hair: hers braided, his curled.

After forging much of the last '60s and early '70s rhythm and blues sound, most successfully with songs like "You're All I Need To Get By," and "Ain't No Mountain High Enough, Ashford-Simpson sailed through the mid-'70s as financially secure artists, sought after as writers and performers. Yet, as their songs crossed over from the Marvin Gayes to the Donny Osmonds, their own records, such as their latest album "So So Satified." scored mainly with the soul and jazz-rock audience.

With their new direction, Ashford Simpson aren't abandoning the black market where their songs have sold 60 million copies. They have four songs on Marvin Gaye's lates album and "Reach Out and Touch" is now a standard in many black churches. But appearing with performers like Seaggs, a white rock singer who has built an even following among blacks and whites, is simply a test.

"In the future I think the labels on most pop music are going to go. Everyone keeps jumping into everyon else's space," said Simpson. "I agree," added Ashford, who then grimaced and aplogized. "I hope we don't sound like we are on quiz show. I agree, she agrees, bingo."

Obviously they are very compatible and view their joint carcers as an extension of thei good times together. "A fusion of forces", is the way Simpson described it. He called it "the flowing toward the color of her music, then the mutual understanding that that's something to say."

Three years ago Ashford and Simpson got married. It had been 10 years since their first hit. "Let's Go Get Stoned", Simpson laughed. "He takes an enormous time thinking. I'm very fast." They live on an 8-acre colonial estate in Connecticut and also have a townhouse in Manhattan that's decorated with art deco lamps. Dali drawings and Oriental rugs.

Despite the familiarities marriage brings, and the schedule a 2-year-old daughter enforces. Ashford-Simpson say they have maintained a spontaneity in their work.

"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," said Ashford. "But I think marriage has changed my style of approach," Corrected Simpson, "What he means is that he used to have more time to do things on his own and we used to have a lot of extra lyrics.

It all sounds too easy. Don't they ever fight. Doesn't he ever pull her braids? "Over dub things," Ashford admitted, and she picked up the thought, "the one inherent problem we have is whose key it should be in".