If Jimmy Carter is guest of honor at next January's Inaugural Ball in Washington, the only Northerners absolutely sure to be invited (aside from the Mondales) are Peter and Cheray Duchin. After all, the society bandleader cracks, Duchins go with Democrats like Lawrence Welk with Republicans. Peter's famed pianist father Eddy serenaded FDR in 1933. Peter's own band played at the party's last inaugural (LBJ in 1965) and latest convention, and he and Cheray also enjoy Democratic social connections. He was raised by his godfather, party patriarch Averell Harriman, and 1959 Deb-of-the-Year Cheray fills their social calendar with famous first names like Jackie, Ethel and Teddy.

Happy days (and nights) will of course still be here for the Duchins even if Carter blows the election. The Peter Duchin Orchestras, which can supply anything from a solo accordion to a full philharmonic, are ah-one and ah-twoing at 400 society and charity do's a year. Peter, 39, fronts some 90 of them personally—for fees ranging as high as $15,000, making him the most pricey dance band in the land.

At times it's all a society drag for Cheray, 35. "I do get tired of hearing questions like, 'Oh, you poor dear, when do you ever get to see him?' " Once Cheray would riposte, "In bed." Actually, she figures, "I see more of Peter than most wives ever see of their husbands. He works at home during the day, and if he's away for more than four days I always go with him."

To ensure their domestic tranquillity, Peter and Cheray in 1972 forsook the harrying Manhattan scene they had adorned for eight years for a pastoral 15-acre estate in suburban Westchester County. Cheray has had the manor house gutted and rebuilt, redecorating all 16 rooms in vivid yellows, greens and blues and scattering around antique quilts, pre-Columbian art and Picasso and Matisse prints. And all, proudly, without a decorator.

Still, the place's most intricate objets remain the Duchins themselves: the slickly handsome Peter, a chunky six-footer; fashionable Cheray, a starved-down 5'8" (since she resumed smoking) from streaked blond coif to her Veneziano sandals. With a live-in housekeeper (and two guards on the premises), Cheray is mistress of, by Peter's count, "four dogs, two goats and three kids." The kids are not the goats' offspring but the Duchins'—Jason, 10, Courtnay, 8, and Colin, 6—and the house was redesigned partially so the children would bunk on the other side of the three-story living room from their parents because, as Cheray explains, "Peter often gets home at 5 a.m., and the kids get up at 6 or 7.1 don't want them disturbing him or vice versa."

At home Peter stashes his five tuxedos in a closet and mucks about an organic garden nourished by his proudest composition: a festering compost pile. For all his Locust Valley lockjaw accent, Duchin insists that his elegant night world is business, not pleasure. He's a daylight outdoorsman at heart. That means exotic fly-fishing jaunts to Norway and family summers on an isolated lake in Canada. (Cheray, who in her first attempt cast an expensive reel right into the river, recently hauled in a 12-pound salmon on a dry fly.)

Cheray's biggest catch, though, was Peter, who, before she set her hook, was regarded as New York's most elegible bon vivant. He'd grown up rich as the only child of his star father and heiress Marjorie Oelrichs, who died six days after his birth. While his dad served in the Navy during World War II, Peter bunked in at the Harrimans' castle, trotting his pet pony through the hallways. His father died tragically from leukemia when Peter was 13, and the 1956 Hollywood account, The Eddy Duchin Story, is now a weekly weeper on late shows everywhere. Peter was initially "really upset at the errors" in the film, especially the suggestion that Dad (portrayed by Tyrone Power) deserted him, but now muses that he was portrayed as "a snot-nosed little kid, and pretty accurately, I would say."

After education at Hotchkiss and Yale, Peter studied classical piano in Paris and played the glockenspiel during an Army hitch in Panama. At school Peter had formed pickup jazz bands, and then in 1961 he brought his first 12-piece band to the St. Regis Hotel's La Maisonette, making it a refuge of the two-step during the first onslaughts of rock.

Cheray and her younger sister Pam (since married to Houston department store heir Robert Sakowitz) are the daughters of George Zauderer, a real estate millionaire and horse owner who nurtured them on Park Avenue. "Now that I think back on those deb parties, it seems silly," admits Cheray. "But at the time it was fun."

Following a year at Bennett Junior College and while an assistant fashion editor at Vogue, she met Peter at a dinner in Palm Beach. She fretted that "every girl I knew had gone out with him, and I knew he was a real heartbreaker." Yet by mid-evening, "I thought, oh, no, here I go." Peter was then operating out of his playboy pad above Carnegie Hall, and, Cheray remembers, "He wasn't ready for marriage—and, come to think of it, neither was I."

Yet, trying to shock Peter into believing that "he couldn't live without me," she impetuously eloped with socialite Frederick Tuck. That, she groans, "was a foolish, childish thing to do," and the hasty union splintered in six months. From then on Cheray concentrated on Peter, "even if it meant asking every poor guy that asked me out to take me to the St. Regis." And, as it turned out, the one society wedding where Peter did not play True Love was his own in 1964—he and Cheray danced to his personal favorite, Count Basie.

Cheray is still so untouched by women's liberation that she can unreservedly say, "My marriage comes first. Anything I would do myself comes second." Thus her days are consumed by her kids and her charities (cancer, African hospitals). Peter is working on a jazz ballet with the Dance Theatre of Harlem, though he talks of eventually breaking into public service with, say, an appointment to the Environmental Protection Agency. But by the time Duchin clears his current performing commitments—they stretch into 1982—his putative sponsor Jimmy Carter would be a second-term lame duck.