When it's right, it's right/Why wait until the middle of a cold, dark night.

It's not gin rummy or a glass of warm milk the Starland Vocal Band was singing about in their suggestive 1976 hit, Afternoon Delight. But that doesn't mean Bill and Taffy Danoff, the founders of Starland, devote their daylight hours to ripping each other's clothes off.

Their 17-month-old daughter, Emma, is evidence of a little healthy prurience in their lives. But the Danoffs are in fact less steamy sybarites than a couple of Virginia squares whose idea of a wild evening is playing Scrabble without a dictionary.

Even the idea for the song, Taffy says, came from a Washington, D.C. restaurant menu headed "Afternoon Delights." She coyly adds to concert audiences: "Then Bill came home and showed me his idea of an afternoon delight. Afterward, instead of having a cigarette, he wrote the song."

Bill's version is less romantic. He says the writing took six months, much of it done while he was watching his beloved Washington Redskins on television. "All that energy coming out of the tube gets my creative juices flowing," he says. "I really wasn't thinking of writing a sexy song."

Whatever the muse, Afternoon Delight offered the kind of four-part harmonies unheard-of since the Mamas & Papas. The resultant single sold 1.5 million copies, the LP 500,000. Most stunningly, the Starland Vocal Band—Taffy, 32, Bill, 30, plus Margot Chapman, 29, and Jon Carroll, 20—copped two Grammys, upsetting rock's supposed shoo-in, Boston, as best new act of 1976. Now they're going to be this summer's Captain & Tennille, as a six-shot replacement series on CBS.

The Danoffs are the kind of "overnight" success that takes a decade to achieve. Before creating Starland two years ago, Bill and Taffy had been singing and living together for a decade (the last five years as husband and wife). While their four forgettable previous LPs were bought, as Taffy jokes, by "just the immediate family," the Danoffs did help create one giant success.

Pals of John Denver since he was still singing with the Mitchell Trio, Bill and Taffy coauthored (with Denver) his breakthrough hit, Take Me Home, Country Roads. "People think John must have screwed us somewhere because he got to be a big star and nobody knows we wrote Country Roads," Bill acknowledges. "But it isn't true. We have a good relationship with John and have spent years defending him in interviews." Denver has in turn booked the Danoffs on his tours and TV shows, recorded a half dozen of Bill's other songs and brought them to his RCA/ Windsong record label.

Bill and Taffy describe their own meeting with Denverian hyperbole. Bill was rigging lights at Georgetown's Cellar Door club when Taffy showed up to try out for a folk group he was assembling. "Bill said he really liked the way my mouth moved when I sang," Taffy says. She liked what she saw, too, and at a demo tape session tried a novel approach. "I said, 'Why don't we turn out all the lights and hold hands around the mike?' It turned into a séance. I got electric shocks up my arm from Bill. It turned out the same thing was happening to him."

A week later they were sharing an apartment—while maintaining separate phones and mailing addresses in a futile effort to keep their Catholic families from catching on. ("Mother, I have something very serious to tell you," Taffy finally said one day. "You're pregnant?" her mother said. "No, it's that Billy and I have been living together." "Oh, I knew that," Mom said. "I thought this was something important.")

Bill was born in Springfield, Mass., son of a hairdresser mother and a stepfather who was a trainman for the old Boston & Albany Railroad. He started studying guitar at 8 and was writing songs at 12. After avoiding the draft by stretching out his studies at Georgetown University's School of Languages and Linguistics (he's 18 months shy of a Ph.D. in Chinese), Bill started full-time composing.

Taffy (born Mary Catherine, she got her nickname from brother Frank, who called his baby sister "Mary Tafferine") is a civil service brat whose father was a National Archives lawyer and mother a typist for the Federal Trade Commission. Educated in parochial schools, as was Bill, she studied French for two years at the College of Steubenville (Ohio) before switching to secretarial jobs at the D.C. headquarters of Blue Cross and the AFL-CIO. It didn't take much encouragement for her to try show business. (She says she didn't get much either, and, at the Grammy show in February, she ruefully thanked "my mother, who warned me not to quit my day job.")

The Danoffs graduated from a basement flat in Georgetown to a small house in D.C. (now rented by Jon and Margot, who started cohabiting in Starland's first year) and, nine months ago, to a $175,000 spread in Washington's Kennedy country, suburban McLean, Va. Taffy and Bill share the 14-room, three-fireplace manor with Emma, her live-in nanny, Ana, and a bizarre knickknack collection that includes Taffy's set of miniature pigs. Bill's conviction that "after a certain point, money is no longer a goal" presumably developed after he purchased a black Mercedes 450 SE sedan.

Among their showbiz friends are Emmylou Harris (with whom Bill wrote her Boulder to Birmingham), Phoebe Snow, and now-separated actors Chris and Susan Sarandon. The Danoffs also have a political alliance with ex-Sen. Fred Harris, for whom they played at populist fund-raisers during his brief 1976 presidential campaign.

Bill and Taffy share the chores at home. She's the family cook who also makes Emma's baby food from scratch; he takes the salad shift. As for the women's movement, Taffy insists, "We were never unliberated."

This summer will be a crucial one for the Danoffs. This month their new album Rear View Mirror will be released, and in June they begin taping their CBS series. Then comes a follow-up tour (Starland's first without Denver). If their triumphs continue the band will move closer to Bill's ultimate fantasy: "To have Starland sing the national anthem a cappella at the Super Bowl. When the Redskins are playing, of course."